Mini Project - MBA Starting Salaries

Setting directory path and reading the file :

setwd("C:/Users/HP/Downloads/Intern/WEEK 4 DAY 1")

mbasalary.df <- read.csv(paste("MBA Starting Salaries Data.csv", sep=""))
View(mbasalary.df)

summary(mbasalary.df)
##       age             sex           gmat_tot        gmat_qpc    
##  Min.   :22.00   Min.   :1.000   Min.   :450.0   Min.   :28.00  
##  1st Qu.:25.00   1st Qu.:1.000   1st Qu.:580.0   1st Qu.:72.00  
##  Median :27.00   Median :1.000   Median :620.0   Median :83.00  
##  Mean   :27.36   Mean   :1.248   Mean   :619.5   Mean   :80.64  
##  3rd Qu.:29.00   3rd Qu.:1.000   3rd Qu.:660.0   3rd Qu.:93.00  
##  Max.   :48.00   Max.   :2.000   Max.   :790.0   Max.   :99.00  
##     gmat_vpc        gmat_tpc        s_avg           f_avg      
##  Min.   :16.00   Min.   : 0.0   Min.   :2.000   Min.   :0.000  
##  1st Qu.:71.00   1st Qu.:78.0   1st Qu.:2.708   1st Qu.:2.750  
##  Median :81.00   Median :87.0   Median :3.000   Median :3.000  
##  Mean   :78.32   Mean   :84.2   Mean   :3.025   Mean   :3.062  
##  3rd Qu.:91.00   3rd Qu.:94.0   3rd Qu.:3.300   3rd Qu.:3.250  
##  Max.   :99.00   Max.   :99.0   Max.   :4.000   Max.   :4.000  
##     quarter         work_yrs         frstlang         salary      
##  Min.   :1.000   Min.   : 0.000   Min.   :1.000   Min.   :     0  
##  1st Qu.:1.250   1st Qu.: 2.000   1st Qu.:1.000   1st Qu.:     0  
##  Median :2.000   Median : 3.000   Median :1.000   Median :   999  
##  Mean   :2.478   Mean   : 3.872   Mean   :1.117   Mean   : 39026  
##  3rd Qu.:3.000   3rd Qu.: 4.000   3rd Qu.:1.000   3rd Qu.: 97000  
##  Max.   :4.000   Max.   :22.000   Max.   :2.000   Max.   :220000  
##      satis      
##  Min.   :  1.0  
##  1st Qu.:  5.0  
##  Median :  6.0  
##  Mean   :172.2  
##  3rd Qu.:  7.0  
##  Max.   :998.0
library(psych)
describe(mbasalary.df)
##          vars   n     mean       sd median  trimmed     mad min    max
## age         1 274    27.36     3.71     27    26.76    2.97  22     48
## sex         2 274     1.25     0.43      1     1.19    0.00   1      2
## gmat_tot    3 274   619.45    57.54    620   618.86   59.30 450    790
## gmat_qpc    4 274    80.64    14.87     83    82.31   14.83  28     99
## gmat_vpc    5 274    78.32    16.86     81    80.33   14.83  16     99
## gmat_tpc    6 274    84.20    14.02     87    86.12   11.86   0     99
## s_avg       7 274     3.03     0.38      3     3.03    0.44   2      4
## f_avg       8 274     3.06     0.53      3     3.09    0.37   0      4
## quarter     9 274     2.48     1.11      2     2.47    1.48   1      4
## work_yrs   10 274     3.87     3.23      3     3.29    1.48   0     22
## frstlang   11 274     1.12     0.32      1     1.02    0.00   1      2
## salary     12 274 39025.69 50951.56    999 33607.86 1481.12   0 220000
## satis      13 274   172.18   371.61      6    91.50    1.48   1    998
##           range  skew kurtosis      se
## age          26  2.16     6.45    0.22
## sex           1  1.16    -0.66    0.03
## gmat_tot    340 -0.01     0.06    3.48
## gmat_qpc     71 -0.92     0.30    0.90
## gmat_vpc     83 -1.04     0.74    1.02
## gmat_tpc     99 -2.28     9.02    0.85
## s_avg         2 -0.06    -0.38    0.02
## f_avg         4 -2.08    10.85    0.03
## quarter       3  0.02    -1.35    0.07
## work_yrs     22  2.78     9.80    0.20
## frstlang      1  2.37     3.65    0.02
## salary   220000  0.70    -1.05 3078.10
## satis       997  1.77     1.13   22.45
attach(mbasalary.df)

Bar charts:

par(mfrow=c(1,2))

hist(mbasalary.df$age, 
     breaks=18, 
     col="gray", 
     xlab="age", 
     main="Histogram")

hist(mbasalary.df$sex, 
     breaks=18, 
     col="gray", 
     xlab="sex", 
     main="Histogram")

hist(mbasalary.df$gmat_tot, 
     breaks=18, 
     col="gray", 
     xlab="gmat_tot", 
     main="Histogram")

hist(mbasalary.df$gmat_qpc, 
     breaks=18, 
     col="gray", 
     xlab="gmat_qpc", 
     main="Histogram")

hist(mbasalary.df$gmat_vpc, 
     breaks=18, 
     col="gray", 
     xlab="gmat_vpc", 
     main="Histogram")

hist(mbasalary.df$gmat_tpc, 
     breaks=18, 
     col="gray", 
     xlab="gmat_tpc", 
     main="Histogram")

hist(mbasalary.df$s_avg, 
     breaks=18, 
     col="gray", 
     xlab="s_avg", 
     main="Histogram")

hist(mbasalary.df$f_avg, 
     breaks=18, 
     col="gray", 
     xlab="f_avg", 
     main="Histogram")

hist(mbasalary.df$quarter, 
     breaks=18, 
     col="gray", 
     xlab="quarter", 
     main="Histogram")

hist(mbasalary.df$work_yrs, 
     breaks=18, 
     col="gray", 
     xlab="work_yrs", 
     main="Histogram")

hist(mbasalary.df$frstlang, 
     breaks=18, 
     col="gray", 
     xlab="frstlang", 
     main="Histogram")

hist(mbasalary.df$salary, 
     breaks=18, 
     col="gray", 
     xlab="salary", 
     main="Histogram")

hist(mbasalary.df$satis, 
     breaks=18, 
     col="gray", 
     xlab="satis", 
     main="Histogram")

Boxplots :

par(mfrow=c(1,2))

boxplot(mbasalary.df$age)

boxplot(mbasalary.df$sex)

boxplot(mbasalary.df$gmat_tot)

boxplot(mbasalary.df$gmat_qpc)

boxplot(mbasalary.df$gmat_vpc)

boxplot(mbasalary.df$gmat_tpc)

boxplot(mbasalary.df$s_avg)

boxplot(mbasalary.df$f_avg)

boxplot(mbasalary.df$quarter)

boxplot(mbasalary.df$work_yrs)

boxplot(mbasalary.df$frstlang)

boxplot(mbasalary.df$salary)

boxplot(mbasalary.df$satis)

Scatterplot matrices:

library(car)
## 
## Attaching package: 'car'
## The following object is masked from 'package:psych':
## 
##     logit
par(mfrow=c(1,1))

scatterplotMatrix(mbasalary.df[,c("age", "gmat_tot")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightpink")

scatterplotMatrix(mbasalary.df[,c("age", "gmat_qpc")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightpink")

scatterplotMatrix(mbasalary.df[,c("age", "gmat_tpc")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightpink")

scatterplotMatrix(mbasalary.df[,c("age", "s_avg")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightpink")

scatterplotMatrix(mbasalary.df[,c("age", "work_yrs")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightpink")

scatterplotMatrix(mbasalary.df[,c("sex", "gmat_qpc")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="mediumblue")

scatterplotMatrix(mbasalary.df[,c("sex", "s_avg")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="mediumblue")

scatterplotMatrix(mbasalary.df[,c("gmat_tot", "gmat_qpc")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcoral")

scatterplotMatrix(mbasalary.df[,c("gmat_tot", "gmat_vpc")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcoral")

scatterplotMatrix(mbasalary.df[,c("gmat_tot", "gmat_vpc")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcoral")

scatterplotMatrix(mbasalary.df[,c("gmat_tot", "work_yrs")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcoral")

scatterplotMatrix(mbasalary.df[,c("gmat_qpc", "gmat_vpc")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcyan")

scatterplotMatrix(mbasalary.df[,c("gmat_qpc", "gmat_tpc")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcyan")

scatterplotMatrix(mbasalary.df[,c("gmat_qpc", "work_yrs")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcyan")

scatterplotMatrix(mbasalary.df[,c("gmat_qpc", "frstlang")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcyan")

scatterplotMatrix(mbasalary.df[,c("gmat_vpc", "gmat_tpc")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightpink")

scatterplotMatrix(mbasalary.df[,c("gmat_vpc", "s_avg")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightpink")

scatterplotMatrix(mbasalary.df[,c("gmat_vpc", "quarter")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightpink")

scatterplotMatrix(mbasalary.df[,c("gmat_vpc", "frstlang")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightpink")

scatterplotMatrix(mbasalary.df[,c("gmat_tpc", "work_yrs")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="mediumblue")

scatterplotMatrix(mbasalary.df[,c("s_avg", "f_avg")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcoral")

scatterplotMatrix(mbasalary.df[,c("s_avg", "quarter")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcoral")

scatterplotMatrix(mbasalary.df[,c("s_avg", "salary")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcoral")

scatterplotMatrix(mbasalary.df[,c("f_avg", "quarter")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcyan")

scatterplotMatrix(mbasalary.df[,c("quarter", "salary")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightpink")

scatterplotMatrix(mbasalary.df[,c("salary", "satis")],spread=FALSE, smoother.args=list(lty=2), main="Scatter Plot Matrix", col="lightcyan")

Corrgram:

library(corrgram)

corrgram(mbasalary.df, order=FALSE, 
         lower.panel=panel.shade,
         upper.panel=panel.pie, 
         text.panel=panel.txt,
         diag.panel=panel.minmax,
         main="Corrgram")

Covariance Correlation Matrix:

#cov(mbasalary.df)
#cor(mbasalary.df)

#corr.test(mbasalary.df, use="complete")


library(corpcor)
library(tseries)

range.names = c("age", "sex", "gmat_tot", "gmat_qpc", "gmat_vpc", "gmat_tpc", "s_avg", "f_avg", "quarter", "work_yrs", "frstlang", "salary", "satis")

covmat = matrix(c(cov(mbasalary.df)), nrow=274, ncol=13)
## Warning in matrix(c(cov(mbasalary.df)), nrow = 274, ncol = 13): data length
## [169] is not a sub-multiple or multiple of the number of rows [274]
#names(range.names) = range.names
#dimnames(covmat) = list(names(range.names), range.names)

#covmat

TASK 2b: WHO GOT HOW MUCH SALARY?

Take a subset of the dataset consisting of only those people who actually got a job. Using this subset of data: Think about the problem as y = f(x), where y = Starting Salary and x = various factors that it could depend upon

Examples: impact of {gender; first language; prior work experience; GMAT performance; MBA performance} etc in determining the Starting Salary

Draw Draw Contingency Tables, as appropriate Run chi-square tests, as appropriate Run t-tests, as appropriate Write more than one regression model as, as y = f(x) where the vector of variables x may be different in different models Estimate the regression models using lm() in R; Compare multiple models (e.g. using the R-Square measure given by lm()); Select the “best” model that “fits” the data;
Interpret the output

subsetone.df <- mbasalary.df[mbasalary.df[ , 12] != "0", ]
View(subsetone.df)


subsettwo.df<- subsetone.df[subsetone.df[ , 12] != "998", ]
View(subsettwo.df)


salariedmbas.df<- subsettwo.df[subsettwo.df[ , 12] != "999", ]
View(salariedmbas.df)

Contingency Table:

library(vcd)
## Loading required package: grid
mytable <- xtabs(~ salary+sex, data=salariedmbas.df)
mytable
##         sex
## salary    1  2
##   64000   0  1
##   77000   1  0
##   78256   0  1
##   82000   0  1
##   85000   1  3
##   86000   0  2
##   88000   0  1
##   88500   1  0
##   90000   3  0
##   92000   2  1
##   93000   2  1
##   95000   4  3
##   96000   3  1
##   96500   1  0
##   97000   2  0
##   98000   6  4
##   99000   0  1
##   100000  4  5
##   100400  1  0
##   101000  0  2
##   101100  1  0
##   101600  1  0
##   102500  1  0
##   103000  1  0
##   104000  2  0
##   105000 11  0
##   106000  2  1
##   107000  1  0
##   107300  1  0
##   107500  1  0
##   108000  2  0
##   110000  0  1
##   112000  3  0
##   115000  5  0
##   118000  1  0
##   120000  3  1
##   126710  1  0
##   130000  1  0
##   145800  1  0
##   146000  1  0
##   162000  1  0
##   220000  0  1
addmargins(mytable)
##         sex
## salary     1   2 Sum
##   64000    0   1   1
##   77000    1   0   1
##   78256    0   1   1
##   82000    0   1   1
##   85000    1   3   4
##   86000    0   2   2
##   88000    0   1   1
##   88500    1   0   1
##   90000    3   0   3
##   92000    2   1   3
##   93000    2   1   3
##   95000    4   3   7
##   96000    3   1   4
##   96500    1   0   1
##   97000    2   0   2
##   98000    6   4  10
##   99000    0   1   1
##   100000   4   5   9
##   100400   1   0   1
##   101000   0   2   2
##   101100   1   0   1
##   101600   1   0   1
##   102500   1   0   1
##   103000   1   0   1
##   104000   2   0   2
##   105000  11   0  11
##   106000   2   1   3
##   107000   1   0   1
##   107300   1   0   1
##   107500   1   0   1
##   108000   2   0   2
##   110000   0   1   1
##   112000   3   0   3
##   115000   5   0   5
##   118000   1   0   1
##   120000   3   1   4
##   126710   1   0   1
##   130000   1   0   1
##   145800   1   0   1
##   146000   1   0   1
##   162000   1   0   1
##   220000   0   1   1
##   Sum     72  31 103
chisq.test(mytable)
## Warning in chisq.test(mytable): Chi-squared approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mytable
## X-squared = 52.681, df = 41, p-value = 0.1045
mytable <- xtabs(~ salary+frstlang, data=salariedmbas.df)
mytable
##         frstlang
## salary    1  2
##   64000   1  0
##   77000   1  0
##   78256   1  0
##   82000   1  0
##   85000   4  0
##   86000   2  0
##   88000   1  0
##   88500   1  0
##   90000   3  0
##   92000   3  0
##   93000   3  0
##   95000   7  0
##   96000   4  0
##   96500   1  0
##   97000   2  0
##   98000   8  2
##   99000   0  1
##   100000  9  0
##   100400  1  0
##   101000  2  0
##   101100  1  0
##   101600  1  0
##   102500  1  0
##   103000  1  0
##   104000  1  1
##   105000 11  0
##   106000  3  0
##   107000  1  0
##   107300  0  1
##   107500  1  0
##   108000  2  0
##   110000  1  0
##   112000  3  0
##   115000  5  0
##   118000  0  1
##   120000  4  0
##   126710  1  0
##   130000  1  0
##   145800  1  0
##   146000  1  0
##   162000  1  0
##   220000  0  1
addmargins(mytable)
##         frstlang
## salary     1   2 Sum
##   64000    1   0   1
##   77000    1   0   1
##   78256    1   0   1
##   82000    1   0   1
##   85000    4   0   4
##   86000    2   0   2
##   88000    1   0   1
##   88500    1   0   1
##   90000    3   0   3
##   92000    3   0   3
##   93000    3   0   3
##   95000    7   0   7
##   96000    4   0   4
##   96500    1   0   1
##   97000    2   0   2
##   98000    8   2  10
##   99000    0   1   1
##   100000   9   0   9
##   100400   1   0   1
##   101000   2   0   2
##   101100   1   0   1
##   101600   1   0   1
##   102500   1   0   1
##   103000   1   0   1
##   104000   1   1   2
##   105000  11   0  11
##   106000   3   0   3
##   107000   1   0   1
##   107300   0   1   1
##   107500   1   0   1
##   108000   2   0   2
##   110000   1   0   1
##   112000   3   0   3
##   115000   5   0   5
##   118000   0   1   1
##   120000   4   0   4
##   126710   1   0   1
##   130000   1   0   1
##   145800   1   0   1
##   146000   1   0   1
##   162000   1   0   1
##   220000   0   1   1
##   Sum     96   7 103
chisq.test(mytable)
## Warning in chisq.test(mytable): Chi-squared approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mytable
## X-squared = 69.847, df = 41, p-value = 0.003296
mytable <- xtabs(~ salary+work_yrs, data=salariedmbas.df)
mytable
##         work_yrs
## salary   0 1 2 3 4 5 6 7 8 10 15 16
##   64000  0 0 1 0 0 0 0 0 0  0  0  0
##   77000  0 0 1 0 0 0 0 0 0  0  0  0
##   78256  0 1 0 0 0 0 0 0 0  0  0  0
##   82000  0 1 0 0 0 0 0 0 0  0  0  0
##   85000  0 1 2 1 0 0 0 0 0  0  0  0
##   86000  0 0 1 1 0 0 0 0 0  0  0  0
##   88000  0 0 0 1 0 0 0 0 0  0  0  0
##   88500  0 0 0 1 0 0 0 0 0  0  0  0
##   90000  0 0 2 0 0 1 0 0 0  0  0  0
##   92000  0 0 3 0 0 0 0 0 0  0  0  0
##   93000  0 0 0 0 1 1 0 0 1  0  0  0
##   95000  1 1 2 2 0 1 0 0 0  0  0  0
##   96000  0 1 2 0 1 0 0 0 0  0  0  0
##   96500  0 0 1 0 0 0 0 0 0  0  0  0
##   97000  0 0 0 1 1 0 0 0 0  0  0  0
##   98000  0 0 7 1 1 0 0 1 0  0  0  0
##   99000  0 0 0 0 0 1 0 0 0  0  0  0
##   100000 0 0 6 1 1 0 1 0 0  0  0  0
##   100400 0 0 0 1 0 0 0 0 0  0  0  0
##   101000 0 0 2 0 0 0 0 0 0  0  0  0
##   101100 0 0 0 0 0 0 0 0 1  0  0  0
##   101600 0 0 0 1 0 0 0 0 0  0  0  0
##   102500 0 0 0 0 0 0 1 0 0  0  0  0
##   103000 0 0 0 1 0 0 0 0 0  0  0  0
##   104000 0 0 0 0 2 0 0 0 0  0  0  0
##   105000 0 0 4 4 0 1 1 0 0  0  0  1
##   106000 0 0 0 0 0 0 2 0 1  0  0  0
##   107000 0 0 1 0 0 0 0 0 0  0  0  0
##   107300 0 0 1 0 0 0 0 0 0  0  0  0
##   107500 0 0 0 1 0 0 0 0 0  0  0  0
##   108000 0 0 0 1 1 0 0 0 0  0  0  0
##   110000 0 0 0 0 0 0 1 0 0  0  0  0
##   112000 0 0 1 0 0 0 1 0 0  0  0  1
##   115000 0 2 0 1 2 0 0 0 0  0  0  0
##   118000 0 0 0 0 0 0 0 0 0  1  0  0
##   120000 0 0 0 1 0 2 0 0 1  0  0  0
##   126710 0 0 0 1 0 0 0 0 0  0  0  0
##   130000 0 0 0 0 1 0 0 0 0  0  0  0
##   145800 0 0 1 0 0 0 0 0 0  0  0  0
##   146000 0 0 0 0 0 0 0 0 0  0  1  0
##   162000 0 1 0 0 0 0 0 0 0  0  0  0
##   220000 0 0 0 0 0 0 0 0 0  0  1  0
addmargins(mytable)
##         work_yrs
## salary     0   1   2   3   4   5   6   7   8  10  15  16 Sum
##   64000    0   0   1   0   0   0   0   0   0   0   0   0   1
##   77000    0   0   1   0   0   0   0   0   0   0   0   0   1
##   78256    0   1   0   0   0   0   0   0   0   0   0   0   1
##   82000    0   1   0   0   0   0   0   0   0   0   0   0   1
##   85000    0   1   2   1   0   0   0   0   0   0   0   0   4
##   86000    0   0   1   1   0   0   0   0   0   0   0   0   2
##   88000    0   0   0   1   0   0   0   0   0   0   0   0   1
##   88500    0   0   0   1   0   0   0   0   0   0   0   0   1
##   90000    0   0   2   0   0   1   0   0   0   0   0   0   3
##   92000    0   0   3   0   0   0   0   0   0   0   0   0   3
##   93000    0   0   0   0   1   1   0   0   1   0   0   0   3
##   95000    1   1   2   2   0   1   0   0   0   0   0   0   7
##   96000    0   1   2   0   1   0   0   0   0   0   0   0   4
##   96500    0   0   1   0   0   0   0   0   0   0   0   0   1
##   97000    0   0   0   1   1   0   0   0   0   0   0   0   2
##   98000    0   0   7   1   1   0   0   1   0   0   0   0  10
##   99000    0   0   0   0   0   1   0   0   0   0   0   0   1
##   100000   0   0   6   1   1   0   1   0   0   0   0   0   9
##   100400   0   0   0   1   0   0   0   0   0   0   0   0   1
##   101000   0   0   2   0   0   0   0   0   0   0   0   0   2
##   101100   0   0   0   0   0   0   0   0   1   0   0   0   1
##   101600   0   0   0   1   0   0   0   0   0   0   0   0   1
##   102500   0   0   0   0   0   0   1   0   0   0   0   0   1
##   103000   0   0   0   1   0   0   0   0   0   0   0   0   1
##   104000   0   0   0   0   2   0   0   0   0   0   0   0   2
##   105000   0   0   4   4   0   1   1   0   0   0   0   1  11
##   106000   0   0   0   0   0   0   2   0   1   0   0   0   3
##   107000   0   0   1   0   0   0   0   0   0   0   0   0   1
##   107300   0   0   1   0   0   0   0   0   0   0   0   0   1
##   107500   0   0   0   1   0   0   0   0   0   0   0   0   1
##   108000   0   0   0   1   1   0   0   0   0   0   0   0   2
##   110000   0   0   0   0   0   0   1   0   0   0   0   0   1
##   112000   0   0   1   0   0   0   1   0   0   0   0   1   3
##   115000   0   2   0   1   2   0   0   0   0   0   0   0   5
##   118000   0   0   0   0   0   0   0   0   0   1   0   0   1
##   120000   0   0   0   1   0   2   0   0   1   0   0   0   4
##   126710   0   0   0   1   0   0   0   0   0   0   0   0   1
##   130000   0   0   0   0   1   0   0   0   0   0   0   0   1
##   145800   0   0   1   0   0   0   0   0   0   0   0   0   1
##   146000   0   0   0   0   0   0   0   0   0   0   1   0   1
##   162000   0   1   0   0   0   0   0   0   0   0   0   0   1
##   220000   0   0   0   0   0   0   0   0   0   0   1   0   1
##   Sum      1   8  38  21  11   7   7   1   4   1   2   2 103
chisq.test(mytable)
## Warning in chisq.test(mytable): Chi-squared approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mytable
## X-squared = 535.23, df = 451, p-value = 0.003809
mytable <- xtabs(~ salary+gmat_vpc, data=salariedmbas.df)
mytable
##         gmat_vpc
## salary   30 33 37 45 50 54 58 62 63 67 71 74 75 78 81 84 87 89 90 91 92 93
##   64000   0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0
##   77000   0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   78256   0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0
##   82000   0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   85000   0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  1  0
##   86000   0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0
##   88000   0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0
##   88500   0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0
##   90000   0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  1  0  0  0  1
##   92000   0  0  0  0  0  0  0  0  0  0  1  1  0  0  0  0  0  0  0  0  0  0
##   93000   0  0  0  0  0  0  0  1  0  0  0  1  0  0  0  0  0  0  0  0  0  0
##   95000   0  0  0  0  0  0  0  1  0  0  2  0  0  0  2  0  0  1  0  0  0  0
##   96000   0  0  0  0  0  0  0  1  0  0  0  0  0  0  1  0  0  1  0  0  0  1
##   96500   1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   97000   0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  1  0  0  0  0  0
##   98000   0  0  1  0  0  0  1  1  0  1  1  0  0  0  1  0  0  0  1  1  0  0
##   99000   0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   100000  0  0  0  0  1  0  0  0  0  1  1  0  0  1  1  2  1  0  0  0  1  0
##   100400  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   101000  0  0  0  0  0  0  0  0  0  1  0  1  0  0  0  0  0  0  0  0  0  0
##   101100  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0
##   101600  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0
##   102500  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   103000  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0
##   104000  0  0  0  1  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   105000  0  0  0  0  1  1  1  0  0  0  2  1  0  0  1  1  1  0  0  1  0  0
##   106000  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0
##   107000  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0
##   107300  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   107500  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0
##   108000  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  1  0  0  0  0  0  0
##   110000  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0
##   112000  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  1  0  0  0  0  1
##   115000  0  1  0  1  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0
##   118000  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0
##   120000  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  1  0  0  0  0  0  0
##   126710  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   130000  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0
##   145800  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0
##   146000  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   162000  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1
##   220000  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##         gmat_vpc
## salary   95 96 97 98 99
##   64000   0  0  0  0  0
##   77000   0  0  0  1  0
##   78256   0  0  0  0  0
##   82000   1  0  0  0  0
##   85000   0  0  0  2  0
##   86000   0  1  0  0  0
##   88000   0  0  0  0  0
##   88500   0  0  0  0  0
##   90000   0  0  0  0  0
##   92000   0  1  0  0  0
##   93000   0  0  0  1  0
##   95000   0  1  0  0  0
##   96000   0  0  0  0  0
##   96500   0  0  0  0  0
##   97000   0  0  0  0  0
##   98000   0  0  0  2  0
##   99000   0  0  0  0  0
##   100000  0  0  0  0  0
##   100400  1  0  0  0  0
##   101000  0  0  0  0  0
##   101100  0  0  0  0  0
##   101600  0  0  0  0  0
##   102500  0  0  1  0  0
##   103000  0  0  0  0  0
##   104000  0  0  0  0  0
##   105000  0  1  0  0  0
##   106000  0  1  0  0  1
##   107000  0  0  0  0  0
##   107300  1  0  0  0  0
##   107500  0  0  0  0  0
##   108000  0  0  0  0  0
##   110000  0  0  0  0  0
##   112000  0  0  0  0  0
##   115000  1  0  0  1  0
##   118000  0  0  0  0  0
##   120000  2  0  0  0  0
##   126710  0  0  0  0  0
##   130000  0  0  0  0  0
##   145800  0  0  0  0  0
##   146000  1  0  0  0  0
##   162000  0  0  0  0  0
##   220000  0  0  0  0  0
addmargins(mytable)
##         gmat_vpc
## salary    30  33  37  45  50  54  58  62  63  67  71  74  75  78  81  84
##   64000    0   0   0   0   0   0   0   0   0   0   0   0   0   1   0   0
##   77000    0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   78256    0   0   0   0   0   0   0   0   0   1   0   0   0   0   0   0
##   82000    0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   85000    0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   86000    0   0   0   0   0   0   0   0   0   0   0   0   0   0   1   0
##   88000    0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   88500    0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   0
##   90000    0   0   0   0   0   0   0   0   0   1   0   0   0   0   0   0
##   92000    0   0   0   0   0   0   0   0   0   0   1   1   0   0   0   0
##   93000    0   0   0   0   0   0   0   1   0   0   0   1   0   0   0   0
##   95000    0   0   0   0   0   0   0   1   0   0   2   0   0   0   2   0
##   96000    0   0   0   0   0   0   0   1   0   0   0   0   0   0   1   0
##   96500    1   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   97000    0   0   0   0   0   0   0   0   0   0   1   0   0   0   0   0
##   98000    0   0   1   0   0   0   1   1   0   1   1   0   0   0   1   0
##   99000    0   0   0   0   0   0   1   0   0   0   0   0   0   0   0   0
##   100000   0   0   0   0   1   0   0   0   0   1   1   0   0   1   1   2
##   100400   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   101000   0   0   0   0   0   0   0   0   0   1   0   1   0   0   0   0
##   101100   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   101600   0   0   0   0   0   0   0   0   0   0   1   0   0   0   0   0
##   102500   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   103000   0   0   0   0   0   0   0   0   1   0   0   0   0   0   0   0
##   104000   0   0   0   1   0   0   1   0   0   0   0   0   0   0   0   0
##   105000   0   0   0   0   1   1   1   0   0   0   2   1   0   0   1   1
##   106000   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   107000   0   0   0   0   0   0   0   0   0   1   0   0   0   0   0   0
##   107300   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   107500   0   0   0   0   0   0   0   0   0   0   0   0   1   0   0   0
##   108000   0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   1
##   110000   0   0   0   0   0   0   0   0   0   0   0   0   0   0   1   0
##   112000   0   0   0   0   0   0   0   0   0   0   0   0   0   0   1   0
##   115000   0   1   0   1   0   0   0   0   0   0   0   0   0   0   1   0
##   118000   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   120000   0   0   0   0   0   0   0   0   0   0   0   0   0   0   1   1
##   126710   0   0   0   0   0   0   1   0   0   0   0   0   0   0   0   0
##   130000   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   145800   0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   0
##   146000   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   162000   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
##   220000   0   0   0   1   0   0   0   0   0   0   0   0   0   0   0   0
##   Sum      1   1   1   3   2   1   5   4   1   6   9   7   1   2  11   5
##         gmat_vpc
## salary    87  89  90  91  92  93  95  96  97  98  99 Sum
##   64000    0   0   0   0   0   0   0   0   0   0   0   1
##   77000    0   0   0   0   0   0   0   0   0   1   0   1
##   78256    0   0   0   0   0   0   0   0   0   0   0   1
##   82000    0   0   0   0   0   0   1   0   0   0   0   1
##   85000    1   0   0   0   1   0   0   0   0   2   0   4
##   86000    0   0   0   0   0   0   0   1   0   0   0   2
##   88000    0   0   0   1   0   0   0   0   0   0   0   1
##   88500    0   0   0   0   0   0   0   0   0   0   0   1
##   90000    0   1   0   0   0   1   0   0   0   0   0   3
##   92000    0   0   0   0   0   0   0   1   0   0   0   3
##   93000    0   0   0   0   0   0   0   0   0   1   0   3
##   95000    0   1   0   0   0   0   0   1   0   0   0   7
##   96000    0   1   0   0   0   1   0   0   0   0   0   4
##   96500    0   0   0   0   0   0   0   0   0   0   0   1
##   97000    1   0   0   0   0   0   0   0   0   0   0   2
##   98000    0   0   1   1   0   0   0   0   0   2   0  10
##   99000    0   0   0   0   0   0   0   0   0   0   0   1
##   100000   1   0   0   0   1   0   0   0   0   0   0   9
##   100400   0   0   0   0   0   0   1   0   0   0   0   1
##   101000   0   0   0   0   0   0   0   0   0   0   0   2
##   101100   0   0   1   0   0   0   0   0   0   0   0   1
##   101600   0   0   0   0   0   0   0   0   0   0   0   1
##   102500   0   0   0   0   0   0   0   0   1   0   0   1
##   103000   0   0   0   0   0   0   0   0   0   0   0   1
##   104000   0   0   0   0   0   0   0   0   0   0   0   2
##   105000   1   0   0   1   0   0   0   1   0   0   0  11
##   106000   1   0   0   0   0   0   0   1   0   0   1   3
##   107000   0   0   0   0   0   0   0   0   0   0   0   1
##   107300   0   0   0   0   0   0   1   0   0   0   0   1
##   107500   0   0   0   0   0   0   0   0   0   0   0   1
##   108000   0   0   0   0   0   0   0   0   0   0   0   2
##   110000   0   0   0   0   0   0   0   0   0   0   0   1
##   112000   1   0   0   0   0   1   0   0   0   0   0   3
##   115000   0   0   0   0   0   0   1   0   0   1   0   5
##   118000   0   1   0   0   0   0   0   0   0   0   0   1
##   120000   0   0   0   0   0   0   2   0   0   0   0   4
##   126710   0   0   0   0   0   0   0   0   0   0   0   1
##   130000   1   0   0   0   0   0   0   0   0   0   0   1
##   145800   0   0   0   0   0   0   0   0   0   0   0   1
##   146000   0   0   0   0   0   0   1   0   0   0   0   1
##   162000   0   0   0   0   0   1   0   0   0   0   0   1
##   220000   0   0   0   0   0   0   0   0   0   0   0   1
##   Sum      7   4   2   3   2   4   7   5   1   7   1 103
chisq.test(mytable)
## Warning in chisq.test(mytable): Chi-squared approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mytable
## X-squared = 1183.3, df = 1066, p-value = 0.006802
mytable <- xtabs(~ salary+quarter, data=salariedmbas.df)
mytable
##         quarter
## salary   1 2 3 4
##   64000  0 0 0 1
##   77000  0 0 0 1
##   78256  0 0 1 0
##   82000  0 1 0 0
##   85000  2 0 0 2
##   86000  1 0 0 1
##   88000  1 0 0 0
##   88500  0 0 1 0
##   90000  0 0 2 1
##   92000  1 1 0 1
##   93000  1 1 1 0
##   95000  3 2 1 1
##   96000  2 1 0 1
##   96500  0 1 0 0
##   97000  0 0 2 0
##   98000  0 3 6 1
##   99000  0 1 0 0
##   100000 3 2 2 2
##   100400 0 0 0 1
##   101000 0 1 1 0
##   101100 0 0 1 0
##   101600 0 0 0 1
##   102500 0 0 1 0
##   103000 0 1 0 0
##   104000 0 1 0 1
##   105000 6 3 1 1
##   106000 2 0 1 0
##   107000 0 1 0 0
##   107300 0 0 1 0
##   107500 1 0 0 0
##   108000 1 0 1 0
##   110000 1 0 0 0
##   112000 1 1 1 0
##   115000 2 2 0 1
##   118000 1 0 0 0
##   120000 4 0 0 0
##   126710 0 0 0 1
##   130000 0 1 0 0
##   145800 0 1 0 0
##   146000 1 0 0 0
##   162000 1 0 0 0
##   220000 0 0 0 1
addmargins(mytable)
##         quarter
## salary     1   2   3   4 Sum
##   64000    0   0   0   1   1
##   77000    0   0   0   1   1
##   78256    0   0   1   0   1
##   82000    0   1   0   0   1
##   85000    2   0   0   2   4
##   86000    1   0   0   1   2
##   88000    1   0   0   0   1
##   88500    0   0   1   0   1
##   90000    0   0   2   1   3
##   92000    1   1   0   1   3
##   93000    1   1   1   0   3
##   95000    3   2   1   1   7
##   96000    2   1   0   1   4
##   96500    0   1   0   0   1
##   97000    0   0   2   0   2
##   98000    0   3   6   1  10
##   99000    0   1   0   0   1
##   100000   3   2   2   2   9
##   100400   0   0   0   1   1
##   101000   0   1   1   0   2
##   101100   0   0   1   0   1
##   101600   0   0   0   1   1
##   102500   0   0   1   0   1
##   103000   0   1   0   0   1
##   104000   0   1   0   1   2
##   105000   6   3   1   1  11
##   106000   2   0   1   0   3
##   107000   0   1   0   0   1
##   107300   0   0   1   0   1
##   107500   1   0   0   0   1
##   108000   1   0   1   0   2
##   110000   1   0   0   0   1
##   112000   1   1   1   0   3
##   115000   2   2   0   1   5
##   118000   1   0   0   0   1
##   120000   4   0   0   0   4
##   126710   0   0   0   1   1
##   130000   0   1   0   0   1
##   145800   0   1   0   0   1
##   146000   1   0   0   0   1
##   162000   1   0   0   0   1
##   220000   0   0   0   1   1
##   Sum     35  25  24  19 103
chisq.test(mytable)
## Warning in chisq.test(mytable): Chi-squared approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mytable
## X-squared = 129.85, df = 123, p-value = 0.3186
detach(mbasalary.df)
attach(salariedmbas.df)

T tests:

library(MASS)
library(psych)

t.test(salariedmbas.df$salary ~ salariedmbas.df$sex, data=salariedmbas.df)
## 
##  Welch Two Sample t-test
## 
## data:  salariedmbas.df$salary by salariedmbas.df$sex
## t = 1.3628, df = 38.115, p-value = 0.1809
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  -3128.55 16021.72
## sample estimates:
## mean in group 1 mean in group 2 
##       104970.97        98524.39
t.test(salariedmbas.df$salary ~ salariedmbas.df$frstlang, data=salariedmbas.df)
## 
##  Welch Two Sample t-test
## 
## data:  salariedmbas.df$salary by salariedmbas.df$frstlang
## t = -1.1202, df = 6.0863, p-value = 0.3049
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  -59933.62  22202.25
## sample estimates:
## mean in group 1 mean in group 2 
##        101748.6        120614.3
t.test(salariedmbas.df$salary, salariedmbas.df$work_yrs, data=salariedmbas.df)
## 
##  Welch Two Sample t-test
## 
## data:  salariedmbas.df$salary and salariedmbas.df$work_yrs
## t = 58.516, df = 102, p-value < 2.2e-16
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##   99534.79 106519.33
## sample estimates:
##    mean of x    mean of y 
## 1.030307e+05 3.679612e+00
t.test(salariedmbas.df$salary, salariedmbas.df$gmat_vpc, data=salariedmbas.df)
## 
##  Welch Two Sample t-test
## 
## data:  salariedmbas.df$salary and salariedmbas.df$gmat_vpc
## t = 58.473, df = 102, p-value < 2.2e-16
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##   99459.9 106444.4
## sample estimates:
##    mean of x    mean of y 
## 103030.73786     78.56311
t.test(salariedmbas.df$salary, salariedmbas.df$quartile, data=salariedmbas.df)
## 
##  One Sample t-test
## 
## data:  salariedmbas.df$salary
## t = 58.518, df = 102, p-value < 2.2e-16
## alternative hypothesis: true mean is not equal to 0
## 95 percent confidence interval:
##   99538.47 106523.01
## sample estimates:
## mean of x 
##  103030.7
detach(salariedmbas.df)
attach(mbasalary.df)

Regression :

fit <-lm(salary ~ sex+frstlang+work_yrs+gmat_tpc+quarter) 

summary(fit)
## 
## Call:
## lm(formula = salary ~ sex + frstlang + work_yrs + gmat_tpc + 
##     quarter)
## 
## Residuals:
##    Min     1Q Median     3Q    Max 
## -56018 -40660 -27819  54841 197132 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)  
## (Intercept)  67808.32   27048.48   2.507   0.0128 *
## sex           5693.06    7134.87   0.798   0.4256  
## frstlang    -11624.18    9603.28  -1.210   0.2272  
## work_yrs      -133.31     966.67  -0.138   0.8904  
## gmat_tpc       -59.63     223.76  -0.267   0.7901  
## quarter      -7009.23    2816.42  -2.489   0.0134 *
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 50530 on 268 degrees of freedom
## Multiple R-squared:  0.03463,    Adjusted R-squared:  0.01662 
## F-statistic: 1.923 on 5 and 268 DF,  p-value: 0.0908
fit$coefficients
##  (Intercept)          sex     frstlang     work_yrs     gmat_tpc 
##  67808.31767   5693.05635 -11624.17549   -133.30707    -59.63415 
##      quarter 
##  -7009.23257
salariedmbas.df$salary
##   [1]  85000  85000  86000  88000  92000  93000  95000  95000  95000  96000
##  [11]  96000 100000 100000 100000 105000 105000 105000 105000 105000 105000
##  [21] 106000 106000 107500 108000 110000 112000 115000 115000 118000 120000
##  [31] 120000 120000 120000 146000 162000  82000  92000  93000  95000  95000
##  [41]  96000  96500  98000  98000  98000  99000 100000 100000 101000 103000
##  [51] 104000 105000 105000 105000 107000 112000 115000 115000 130000 145800
##  [61]  78256  88500  90000  90000  93000  95000  97000  97000  98000  98000
##  [71]  98000  98000  98000  98000 100000 100000 101000 101100 102500 105000
##  [81] 106000 107300 108000 112000  64000  77000  85000  85000  86000  90000
##  [91]  92000  95000  96000  98000 100000 100000 100400 101600 104000 105000
## [101] 115000 126710 220000
fitted(fit)
##        1        2        3        4        5        6        7        8 
## 55106.24 49413.18 48936.11 50262.10 54450.26 49174.64 49413.18 54808.07 
##        9       10       11       12       13       14       15       16 
## 37669.74 48876.47 48697.57 55165.87 48623.90 48697.57 54422.18 54808.07 
##       17       18       19       20       21       22       23       24 
## 54362.55 37834.60 49293.91 49385.10 55435.96 48564.26 37206.70 56018.27 
##       25       26       27       28       29       30       31       32 
## 49816.58 49013.26 54934.29 48297.65 48508.11 54334.74 54439.70 55067.60 
##       33       34       35       36       37       38       39       40 
## 53282.05 47104.84 54822.10 54450.26 54569.53 54615.12 48757.20 54706.32 
##       41       42       43       44       45       46       47       48 
## 49202.72 56134.06 56523.42 49188.68 55197.43 54748.43 50367.33 48939.59 
##       49       50       51       52       53       54       55       56 
## 49055.38 50412.92 49995.48 49949.89 49251.80 49595.56 48613.34 54036.30 
##       57       58       59       60       61       62       63       64 
## 49041.34 49518.41 54334.47 47785.42 49862.18 48890.51 36722.55 49518.41 
##       65       66       67       68       69       70       71       72 
## 48357.28 49192.16 53829.32 47441.65 48890.51 42775.79 42105.78 32119.80 
##       73       74       75       76       77       78       79       80 
## 43119.56 42537.26 48619.67 41986.51 41807.61 41614.67 35936.12 41747.97 
##       81       82       83       84       85       86       87       88 
## 47784.79 30243.07 41807.61 41674.30 41926.87 42940.66 41674.30 48858.21 
##       89       90       91       92       93       94       95       96 
## 43165.15 32004.01 41688.34 41288.42 42628.45 42018.07 43031.85 38770.48 
##       97       98       99      100      101      102      103      104 
## 42018.07 47756.72 41600.63 42119.82 30930.60 43912.32 47665.53 41797.05 
##      105      106      107      108      109      110      111      112 
## 42228.52 42674.04 41600.63 41600.63 46956.87 42916.06 40891.97 48921.32 
##      113      114      115      116      117      118      119      120 
## 39913.23 40418.38 47753.24 48097.00 42916.06 41926.87 42330.28 43298.46 
##      121      122      123      124      125      126      127      128 
## 44491.14 42761.75 43119.56 37055.13 36549.98 48633.71 43031.85 48097.00 
##      129      130      131      132      133      134      135      136 
## 42211.01 43031.85 41733.93 42151.37 41611.06 42642.48 41393.65 42537.26 
##      137      138      139      140      141      142      143      144 
## 42018.07 41779.53 42403.95 34812.41 29165.43 34679.11 34858.01 40372.16 
##      145      146      147      148      149      150      151      152 
## 35170.22 35766.56 40849.24 35366.64 35275.45 36334.82 34872.05 34843.97 
##      153      154      155      156      157      158      159      160 
## 23517.96 24665.05 34591.39 23219.79 35082.51 34889.56 36022.61 36706.67 
##      161      162      163      164      165      166      167      168 
## 23742.46 41670.07 35321.04 35036.91 42027.88 34945.72 23563.56 40568.58 
##      169      170      171      172      173      174      175      176 
## 41522.73 29463.60 35499.94 34903.60 36289.23 35187.74 35440.31 38109.81 
##      177      178      179      180      181      182      183      184 
## 23146.12 40880.79 36548.76 23995.04 35962.98 35682.33 34254.59 34121.28 
##      185      186      187      188      189      190      191      192 
## 35233.21 42950.47 35261.41 35812.15 35275.45 35128.10 41582.36 35068.47 
##      193      194      195      196      197      198      199      200 
## 35798.12 40551.06 41982.28 41624.48 23174.20 35187.74 34012.57 34545.80 
##      201      202      203      204      205      206      207      208 
## 40968.50 41207.04 34117.80 34324.78 35931.42 34324.78 23353.10 35843.71 
##      209      210      211      212      213      214      215      216 
## 34798.37 28445.12 28280.25 28564.39 27669.87 33587.43 28280.25 28609.98 
##      217      218      219      220      221      222      223      224 
## 17119.11 27862.81 27908.41 31279.48 17522.51 28624.02 28967.79 28609.98 
##      225      226      227      228      229      230      231      232 
## 33468.16 27701.43 34913.42 27403.26 27880.33 29055.50 28399.52 27508.49 
##      233      234      235      236      237      238      239      240 
## 28788.88 28820.44 28252.18 27136.64 33173.73 29343.11 27122.61 28132.91 
##      241      242      243      244      245      246      247      248 
## 27775.10 16775.35 33275.22 28027.68 17434.80 21980.77 27599.68 28329.33 
##      249      250      251      252      253      254      255      256 
## 26870.03 29234.40 27420.78 17210.30 18329.31 28301.25 33022.64 35032.69 
##      257      258      259      260      261      262      263      264 
## 27908.41 33229.62 28266.21 33766.33 27627.76 27908.41 28445.12 28624.02 
##      265      266      267      268      269      270      271      272 
## 29101.09 34257.44 33720.73 28132.91 28013.64 17985.55 28922.19 29564.13 
##      273      274 
## 29325.59 22868.20
residuals(fit)
##         1         2         3         4         5         6         7 
## -55106.24 -49413.18 -48936.11 -50262.10 -53451.26 -49174.64 -49413.18 
##         8         9        10        11        12        13        14 
## -54808.07 -36670.74 -47878.47 -47699.57 -54167.87 -47625.90 -47699.57 
##        15        16        17        18        19        20        21 
## -53424.18 -53810.07 -53364.55 -36836.60 -48295.91 -48387.10 -54436.96 
##        22        23        24        25        26        27        28 
## -48564.26 -37206.70 -56018.27 -49816.58 -48014.26 -54934.29 -48297.65 
##        29        30        31        32        33        34        35 
## -48508.11 -53335.74 -54439.70 -55067.60 -53282.05 -47104.84  30177.90 
##        36        37        38        39        40        41        42 
##  30549.74  31430.47  33384.88  43242.80  38293.68  45797.28  38865.94 
##        43        44        45        46        47        48        49 
##  38476.58  46811.32  40802.57  45251.57  49632.67  51060.41  55944.62 
##        50        51        52        53        54        55        56 
##  54587.08  55004.52  55050.11  55748.20  55404.44  57386.66  51963.70 
##        57        58        59        60        61        62        63 
##  58458.66  58481.59  55665.53  64214.58  65137.82  66109.49  81277.45 
##        64        65        66        67        68        69        70 
##  70481.59  71642.72  70807.84  66170.68  98558.35 113109.49 -42775.79 
##        71        72        73        74        75        76        77 
## -42105.78 -32119.80 -43119.56 -42537.26 -48619.67 -41986.51 -41807.61 
##        78        79        80        81        82        83        84 
## -40615.67 -34938.12 -40749.97 -46786.79 -29245.07 -40809.61 -40676.30 
##        85        86        87        88        89        90        91 
## -40928.87 -41942.66 -40675.30 -48858.21 -43165.15 -32004.01 -40689.34 
##        92        93        94        95        96        97        98 
## -41288.42 -42628.45 -41020.07 -42033.85 -37772.48 -42018.07 -47756.72 
##        99       100       101       102       103       104       105 
## -40601.63 -42119.82 -29931.60 -43912.32 -47665.53 -41797.05 -41229.52 
##       106       107       108       109       110       111       112 
## -42674.04 -41600.63 -40601.63 -46956.87 -42916.06 -40891.97 -48921.32 
##       113       114       115       116       117       118       119 
## -39913.23 -40418.38  34246.76  43903.00  50083.94  53073.13  52669.72 
##       120       121       122       123       124       125       126 
##  52701.54  52008.86  55238.25  54880.44  60944.87  62450.02  51366.29 
##       127       128       129       130       131       132       133 
##  56968.15  52903.00  60788.99  60968.15  63266.07  62848.63  63388.94 
##       134       135       136       137       138       139       140 
##  64357.52  70606.35  72462.74  72981.93  88220.47 103396.05 -34812.41 
##       141       142       143       144       145       146       147 
## -29165.43 -34679.11 -34858.01 -40372.16 -34171.22 -35766.56 -40849.24 
##       148       149       150       151       152       153       154 
## -34368.64 -34277.45 -36334.82 -34872.05 -33844.97 -22519.96 -23667.05 
##       155       156       157       158       159       160       161 
## -33593.39 -22221.79 -34084.51 -33890.56 -36022.61 -36706.67 -22743.46 
##       162       163       164       165       166       167       168 
## -41670.07 -35321.04 -35036.91 -42027.88 -33946.72 -23563.56 -40568.58 
##       169       170       171       172       173       174       175 
## -41522.73 -28464.60 -34501.94 -33905.60 -35291.23 -34189.74 -34442.31 
##       176       177       178       179       180       181       182 
## -37111.81 -22148.12 -39882.79 -35549.76 -23995.04 -34963.98 -35682.33 
##       183       184       185       186       187       188       189 
## -34254.59 -34121.28 -35233.21  35305.53  53238.59  54187.85  54724.55 
##       190       191       192       193       194       195       196 
##  57871.90  53417.64  61931.53  61201.88  57448.94  56017.72  56375.52 
##       197       198       199       200       201       202       203 
##  74825.80  62812.26  63987.43  65454.20  59031.50  59792.96  66982.20 
##       204       205       206       207       208       209       210 
##  68175.22  69068.58  71675.22  83946.90  72156.29  77201.63 -27447.12 
##       211       212       213       214       215       216       217 
## -27282.25 -27565.39 -27669.87 -32588.43 -27282.25 -27611.98 -16120.11 
##       218       219       220       221       222       223       224 
## -27862.81 -27908.41 -31279.48 -16523.51 -28624.02 -27968.79 -27611.98 
##       225       226       227       228       229       230       231 
## -32470.16 -26702.43 -34913.42 -26404.26 -27880.33 -29055.50 -27400.52 
##       232       233       234       235       236       237       238 
## -27508.49 -28788.88 -28820.44 -27253.18 -27136.64 -33173.73 -29343.11 
##       239       240       241       242       243       244       245 
## -26123.61 -27133.91 -27775.10 -16775.35 -33275.22 -28027.68 -16435.80 
##       246       247       248       249       250       251       252 
## -20981.77 -26601.68 -27331.33 -25872.03 -29234.40 -26421.78 -16211.30 
##       253       254       255       256       257       258       259 
## -18329.31 -28301.25 -33022.64  28967.31  49091.59  51770.38  56733.79 
##       260       261       262       263       264       265       266 
##  52233.67  62372.24  64091.59  66554.88  67375.98  68898.91  65742.56 
##       267       268       269       270       271       272       273 
##  66279.27  72267.09  73586.36  86014.45  76077.81  85435.87  97384.41 
##       274 
## 197131.80

Plots:

par(mfrow=c(1,2))

plot(salariedmbas.df$salary,salariedmbas.df$sex,main="Plot 1",xlab="Salary",ylab="Sex") 

plot(salariedmbas.df$salary,salariedmbas.df$frstlang,main="Plot 2",xlab="Salary",ylab="First language") 

plot(salariedmbas.df$salary,salariedmbas.df$work_yrs,main="Plot 3",xlab="Salary",ylab="Work exp") 

plot(salariedmbas.df$salary,salariedmbas.df$gmat_tpc,main="Plot 4",xlab="Salary",ylab="GMAT Percentile") 

plot(salariedmbas.df$salary,salariedmbas.df$quarter,main="Plot 5",xlab="Salary",ylab="Quarter") 

plot(salariedmbas.df$salary,salariedmbas.df$gmat_tot,main="Plot 6",xlab="Salary",ylab="GMAT Total") 

plot(salariedmbas.df$salary,salariedmbas.df$age,main="Plot 7",xlab="Salary",ylab="age") 

Salary == 0 (Jobless)

joblessmbas.df <- mbasalary.df[mbasalary.df[ , 12] == "0", ]
View(joblessmbas.df)

Contingency tables :

mytable <- xtabs(~ gmat_vpc+quarter, data=salariedmbas.df)
mytable
##         quarter
## gmat_vpc 1 2 3 4
##       30 0 1 0 0
##       33 1 0 0 0
##       37 0 1 0 0
##       45 0 0 0 3
##       50 2 0 0 0
##       54 0 0 1 0
##       58 0 4 0 1
##       62 1 1 0 2
##       63 0 1 0 0
##       67 0 2 4 0
##       71 2 2 3 2
##       74 2 3 2 0
##       75 1 0 0 0
##       78 0 0 0 2
##       81 5 3 0 3
##       84 3 0 1 1
##       87 1 2 3 1
##       89 2 1 0 1
##       90 0 0 2 0
##       91 2 0 1 0
##       92 1 0 1 0
##       93 2 1 1 0
##       95 3 2 1 1
##       96 4 1 0 0
##       97 0 0 1 0
##       98 3 0 2 2
##       99 0 0 1 0
addmargins(mytable)
##         quarter
## gmat_vpc   1   2   3   4 Sum
##      30    0   1   0   0   1
##      33    1   0   0   0   1
##      37    0   1   0   0   1
##      45    0   0   0   3   3
##      50    2   0   0   0   2
##      54    0   0   1   0   1
##      58    0   4   0   1   5
##      62    1   1   0   2   4
##      63    0   1   0   0   1
##      67    0   2   4   0   6
##      71    2   2   3   2   9
##      74    2   3   2   0   7
##      75    1   0   0   0   1
##      78    0   0   0   2   2
##      81    5   3   0   3  11
##      84    3   0   1   1   5
##      87    1   2   3   1   7
##      89    2   1   0   1   4
##      90    0   0   2   0   2
##      91    2   0   1   0   3
##      92    1   0   1   0   2
##      93    2   1   1   0   4
##      95    3   2   1   1   7
##      96    4   1   0   0   5
##      97    0   0   1   0   1
##      98    3   0   2   2   7
##      99    0   0   1   0   1
##      Sum  35  25  24  19 103
chisq.test(mytable)
## Warning in chisq.test(mytable): Chi-squared approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mytable
## X-squared = 101.86, df = 78, p-value = 0.03621
mytable <- xtabs(~ gmat_vpc+work_yrs, data=salariedmbas.df)
mytable
##         work_yrs
## gmat_vpc 0 1 2 3 4 5 6 7 8 10 15 16
##       30 0 0 1 0 0 0 0 0 0  0  0  0
##       33 0 0 0 0 1 0 0 0 0  0  0  0
##       37 0 0 0 1 0 0 0 0 0  0  0  0
##       45 0 0 0 1 1 0 0 0 0  0  1  0
##       50 0 0 1 1 0 0 0 0 0  0  0  0
##       54 0 0 1 0 0 0 0 0 0  0  0  0
##       58 0 0 1 1 1 1 0 0 0  0  0  1
##       62 0 0 2 1 0 0 0 0 1  0  0  0
##       63 0 0 0 1 0 0 0 0 0  0  0  0
##       67 0 1 3 0 2 0 0 0 0  0  0  0
##       71 0 0 4 3 0 1 1 0 0  0  0  0
##       74 0 0 3 3 1 0 0 0 0  0  0  0
##       75 0 0 0 1 0 0 0 0 0  0  0  0
##       78 0 0 2 0 0 0 0 0 0  0  0  0
##       81 0 2 5 1 0 1 1 0 0  0  0  1
##       84 0 0 2 1 1 0 1 0 0  0  0  0
##       87 0 0 3 1 2 0 1 0 0  0  0  0
##       89 0 0 1 0 1 1 0 0 0  1  0  0
##       90 0 0 1 0 0 0 0 0 1  0  0  0
##       91 0 0 1 1 0 1 0 0 0  0  0  0
##       92 0 1 0 1 0 0 0 0 0  0  0  0
##       93 0 2 1 0 0 0 1 0 0  0  0  0
##       95 0 1 1 1 1 1 0 0 1  0  1  0
##       96 1 0 2 1 0 0 0 0 1  0  0  0
##       97 0 0 0 0 0 0 1 0 0  0  0  0
##       98 0 1 3 1 0 1 0 1 0  0  0  0
##       99 0 0 0 0 0 0 1 0 0  0  0  0
addmargins(mytable)
##         work_yrs
## gmat_vpc   0   1   2   3   4   5   6   7   8  10  15  16 Sum
##      30    0   0   1   0   0   0   0   0   0   0   0   0   1
##      33    0   0   0   0   1   0   0   0   0   0   0   0   1
##      37    0   0   0   1   0   0   0   0   0   0   0   0   1
##      45    0   0   0   1   1   0   0   0   0   0   1   0   3
##      50    0   0   1   1   0   0   0   0   0   0   0   0   2
##      54    0   0   1   0   0   0   0   0   0   0   0   0   1
##      58    0   0   1   1   1   1   0   0   0   0   0   1   5
##      62    0   0   2   1   0   0   0   0   1   0   0   0   4
##      63    0   0   0   1   0   0   0   0   0   0   0   0   1
##      67    0   1   3   0   2   0   0   0   0   0   0   0   6
##      71    0   0   4   3   0   1   1   0   0   0   0   0   9
##      74    0   0   3   3   1   0   0   0   0   0   0   0   7
##      75    0   0   0   1   0   0   0   0   0   0   0   0   1
##      78    0   0   2   0   0   0   0   0   0   0   0   0   2
##      81    0   2   5   1   0   1   1   0   0   0   0   1  11
##      84    0   0   2   1   1   0   1   0   0   0   0   0   5
##      87    0   0   3   1   2   0   1   0   0   0   0   0   7
##      89    0   0   1   0   1   1   0   0   0   1   0   0   4
##      90    0   0   1   0   0   0   0   0   1   0   0   0   2
##      91    0   0   1   1   0   1   0   0   0   0   0   0   3
##      92    0   1   0   1   0   0   0   0   0   0   0   0   2
##      93    0   2   1   0   0   0   1   0   0   0   0   0   4
##      95    0   1   1   1   1   1   0   0   1   0   1   0   7
##      96    1   0   2   1   0   0   0   0   1   0   0   0   5
##      97    0   0   0   0   0   0   1   0   0   0   0   0   1
##      98    0   1   3   1   0   1   0   1   0   0   0   0   7
##      99    0   0   0   0   0   0   1   0   0   0   0   0   1
##      Sum   1   8  38  21  11   7   7   1   4   1   2   2 103
chisq.test(mytable)
## Warning in chisq.test(mytable): Chi-squared approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mytable
## X-squared = 238.3, df = 286, p-value = 0.9817
mytable <- xtabs(~ work_yrs+quarter, data=salariedmbas.df)
mytable
##         quarter
## work_yrs  1  2  3  4
##       0   1  0  0  0
##       1   5  2  1  0
##       2   7 10 11 10
##       3   7  5  3  6
##       4   2  4  4  1
##       5   4  1  1  1
##       6   4  1  2  0
##       7   0  0  1  0
##       8   2  1  1  0
##       10  1  0  0  0
##       15  1  0  0  1
##       16  1  1  0  0
addmargins(mytable)
##         quarter
## work_yrs   1   2   3   4 Sum
##      0     1   0   0   0   1
##      1     5   2   1   0   8
##      2     7  10  11  10  38
##      3     7   5   3   6  21
##      4     2   4   4   1  11
##      5     4   1   1   1   7
##      6     4   1   2   0   7
##      7     0   0   1   0   1
##      8     2   1   1   0   4
##      10    1   0   0   0   1
##      15    1   0   0   1   2
##      16    1   1   0   0   2
##      Sum  35  25  24  19 103
chisq.test(mytable)
## Warning in chisq.test(mytable): Chi-squared approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mytable
## X-squared = 29.47, df = 33, p-value = 0.6436
mytable <- xtabs(~ work_yrs+age, data=salariedmbas.df)
mytable
##         age
## work_yrs 22 23 24 25 26 27 28 29 30 31 32 33 34 39 40
##       0   0  0  1  0  0  0  0  0  0  0  0  0  0  0  0
##       1   1  1  1  3  1  1  0  0  0  0  0  0  0  0  0
##       2   0  4 13 12  5  3  0  0  0  0  1  0  0  0  0
##       3   0  0  1  7  6  5  1  1  0  0  0  0  0  0  0
##       4   0  0  0  1  2  3  3  0  0  2  0  0  0  0  0
##       5   0  0  0  0  0  1  3  1  2  0  0  0  0  0  0
##       6   0  0  0  0  0  1  1  2  2  1  0  0  0  0  0
##       7   0  0  0  0  0  0  0  1  0  0  0  0  0  0  0
##       8   0  0  0  0  0  0  0  1  2  1  0  0  0  0  0
##       10  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0
##       15  0  0  0  0  0  0  0  0  0  0  0  0  0  0  2
##       16  0  0  0  0  0  0  0  0  0  0  0  0  1  1  0
addmargins(mytable)
##         age
## work_yrs  22  23  24  25  26  27  28  29  30  31  32  33  34  39  40 Sum
##      0     0   0   1   0   0   0   0   0   0   0   0   0   0   0   0   1
##      1     1   1   1   3   1   1   0   0   0   0   0   0   0   0   0   8
##      2     0   4  13  12   5   3   0   0   0   0   1   0   0   0   0  38
##      3     0   0   1   7   6   5   1   1   0   0   0   0   0   0   0  21
##      4     0   0   0   1   2   3   3   0   0   2   0   0   0   0   0  11
##      5     0   0   0   0   0   1   3   1   2   0   0   0   0   0   0   7
##      6     0   0   0   0   0   1   1   2   2   1   0   0   0   0   0   7
##      7     0   0   0   0   0   0   0   1   0   0   0   0   0   0   0   1
##      8     0   0   0   0   0   0   0   1   2   1   0   0   0   0   0   4
##      10    0   0   0   0   0   0   0   0   0   0   0   1   0   0   0   1
##      15    0   0   0   0   0   0   0   0   0   0   0   0   0   0   2   2
##      16    0   0   0   0   0   0   0   0   0   0   0   0   1   1   0   2
##      Sum   1   5  16  23  14  14   8   6   6   4   1   1   1   1   2 103
chisq.test(mytable)
## Warning in chisq.test(mytable): Chi-squared approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mytable
## X-squared = 462.81, df = 154, p-value < 2.2e-16
mytable <- xtabs(~ sex+gmat_vpc, data=salariedmbas.df)
mytable
##    gmat_vpc
## sex 30 33 37 45 50 54 58 62 63 67 71 74 75 78 81 84 87 89 90 91 92 93 95
##   1  1  1  0  2  2  1  4  3  1  4  6  5  1  0  7  4  5  3  2  1  1  4  5
##   2  0  0  1  1  0  0  1  1  0  2  3  2  0  2  4  1  2  1  0  2  1  0  2
##    gmat_vpc
## sex 96 97 98 99
##   1  4  1  3  1
##   2  1  0  4  0
addmargins(mytable)
##      gmat_vpc
## sex    30  33  37  45  50  54  58  62  63  67  71  74  75  78  81  84  87
##   1     1   1   0   2   2   1   4   3   1   4   6   5   1   0   7   4   5
##   2     0   0   1   1   0   0   1   1   0   2   3   2   0   2   4   1   2
##   Sum   1   1   1   3   2   1   5   4   1   6   9   7   1   2  11   5   7
##      gmat_vpc
## sex    89  90  91  92  93  95  96  97  98  99 Sum
##   1     3   2   1   1   4   5   4   1   3   1  72
##   2     1   0   2   1   0   2   1   0   4   0  31
##   Sum   4   2   3   2   4   7   5   1   7   1 103
chisq.test(mytable)
## Warning in chisq.test(mytable): Chi-squared approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mytable
## X-squared = 19.287, df = 26, p-value = 0.8241
mytable <- xtabs(~ work_yrs+quarter, data=salariedmbas.df)
mytable
##         quarter
## work_yrs  1  2  3  4
##       0   1  0  0  0
##       1   5  2  1  0
##       2   7 10 11 10
##       3   7  5  3  6
##       4   2  4  4  1
##       5   4  1  1  1
##       6   4  1  2  0
##       7   0  0  1  0
##       8   2  1  1  0
##       10  1  0  0  0
##       15  1  0  0  1
##       16  1  1  0  0
addmargins(mytable)
##         quarter
## work_yrs   1   2   3   4 Sum
##      0     1   0   0   0   1
##      1     5   2   1   0   8
##      2     7  10  11  10  38
##      3     7   5   3   6  21
##      4     2   4   4   1  11
##      5     4   1   1   1   7
##      6     4   1   2   0   7
##      7     0   0   1   0   1
##      8     2   1   1   0   4
##      10    1   0   0   0   1
##      15    1   0   0   1   2
##      16    1   1   0   0   2
##      Sum  35  25  24  19 103
chisq.test(mytable)
## Warning in chisq.test(mytable): Chi-squared approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mytable
## X-squared = 29.47, df = 33, p-value = 0.6436

Linear Model Regression:

salarymention <- mbasalary.df[which(mbasalary.df$salary!='998' && mbasalary.df$salary!='999'),]

salarymention$salary[salarymention$salary>0] = 1

salarymention$salary[salarymention$salary < 1] = 0

library(ROCR)
## Loading required package: gplots
## 
## Attaching package: 'gplots'
## The following object is masked from 'package:stats':
## 
##     lowess
train=salarymention[1:96,]
test=salarymention[97:193,]

formula=salary~age+sex+work_yrs+frstlang+gmat_tot+gmat_qpc+gmat_vpc+gmat_tpc+f_avg+s_avg+quarter+frstlang+satis

x=glm(formula = formula, family = binomial(link = "logit"), data = train)

summary(x)
## 
## Call:
## glm(formula = formula, family = binomial(link = "logit"), data = train)
## 
## Deviance Residuals: 
## [1]  0
## 
## Coefficients: (12 not defined because of singularities)
##             Estimate Std. Error z value Pr(>|z|)
## (Intercept)   -22.57   48196.14       0        1
## age               NA         NA      NA       NA
## sex               NA         NA      NA       NA
## work_yrs          NA         NA      NA       NA
## frstlang          NA         NA      NA       NA
## gmat_tot          NA         NA      NA       NA
## gmat_qpc          NA         NA      NA       NA
## gmat_vpc          NA         NA      NA       NA
## gmat_tpc          NA         NA      NA       NA
## f_avg             NA         NA      NA       NA
## s_avg             NA         NA      NA       NA
## quarter           NA         NA      NA       NA
## satis             NA         NA      NA       NA
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 0.0000e+00  on 0  degrees of freedom
## Residual deviance: 3.1675e-10  on 0  degrees of freedom
##   (95 observations deleted due to missingness)
## AIC: 2
## 
## Number of Fisher Scoring iterations: 21
anova(x, test = "Chisq")
## Analysis of Deviance Table
## 
## Model: binomial, link: logit
## 
## Response: salary
## 
## Terms added sequentially (first to last)
## 
## 
##          Df Deviance Resid. Df Resid. Dev Pr(>Chi)
## NULL                         0 0.0000e+00         
## age       0        0         0 3.1675e-10         
## sex       0        0         0 3.1675e-10         
## work_yrs  0        0         0 3.1675e-10         
## frstlang  0        0         0 3.1675e-10         
## gmat_tot  0        0         0 3.1675e-10         
## gmat_qpc  0        0         0 3.1675e-10         
## gmat_vpc  0        0         0 3.1675e-10         
## gmat_tpc  0        0         0 3.1675e-10         
## f_avg     0        0         0 3.1675e-10         
## s_avg     0        0         0 3.1675e-10         
## quarter   0        0         0 3.1675e-10         
## satis     0        0         0 3.1675e-10

Observation: Salary depends on Work Experience, GMAT Total, GMAT Percentile and Age.