Reading data into R

mba=read.csv(paste("MBA Starting Salaries Data.csv",sep=""),)
View(mba)

Summary

summary(mba)
##       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

boxplot

boxplot(mba)

pairs(mba[,c(3:6,10:13)])

library("knitr")
library("corrgram")
corrgram(mba, order=TRUE,main="Corrgram of Mba Salaries",
         lower.panel=panel.shade, upper.panel=panel.pie,
         text.panel=panel.txt)

Creating variance covariance matrix

cov(mba)
##                    age           sex      gmat_tot      gmat_qpc
## age       1.376904e+01 -4.513248e-02 -3.115879e+01 -1.192655e+01
## sex      -4.513248e-02  1.872677e-01 -1.328841e+00 -1.053769e+00
## gmat_tot -3.115879e+01 -1.328841e+00  3.310688e+03  6.200233e+02
## gmat_qpc -1.192655e+01 -1.053769e+00  6.200233e+02  2.210731e+02
## gmat_vpc -2.763643e+00  5.463758e-01  7.260006e+02  3.814826e+01
## gmat_tpc -8.839978e+00 -4.908960e-02  6.839911e+02  1.357997e+02
## s_avg     2.116874e-01  2.096227e-02  2.480257e+00 -1.691233e-01
## f_avg    -3.399348e-02  2.082698e-02  3.154688e+00  5.753854e-01
## quarter  -2.045935e-01 -6.414267e-02 -5.891153e+00  6.001979e-01
## work_yrs  1.029494e+01 -1.580172e-02 -3.391634e+01 -1.137186e+01
## frstlang  6.796610e-02  2.138980e-04 -2.499933e+00  6.646346e-01
## salary   -1.183042e+04  1.518264e+03 -1.611600e+05 -3.335823e+04
## satis    -1.763499e+02 -8.780808e+00  1.765263e+03  3.348371e+02
##               gmat_vpc     gmat_tpc         s_avg        f_avg
## age         -2.7636427   -8.8399775    0.21168739  -0.03399348
## sex          0.5463758   -0.0490896    0.02096227   0.02082698
## gmat_tot   726.0006417  683.9910698    2.48025721   3.15468838
## gmat_qpc    38.1482581  135.7996845   -0.16912329   0.57538542
## gmat_vpc   284.2481217  157.4932488    1.31357023   0.67207000
## gmat_tpc   157.4932488  196.6057057    0.62710008   0.58698618
## s_avg        1.3135702    0.6271001    0.14521760   0.11016898
## f_avg        0.6720700    0.5869862    0.11016898   0.27567237
## quarter     -3.2676666   -1.2923719   -0.32237213  -0.26080880
## work_yrs    -3.6181653   -7.8575172    0.15926392  -0.06628700
## frstlang    -2.1145691   -0.4663244   -0.01671372  -0.00626026
## salary   -5273.8523836 3522.7500067 2831.60098580 787.65597177
## satis      392.3562739  484.2466779   -4.62884495   2.12532927
##                quarter      work_yrs      frstlang        salary
## age      -2.045935e-01   10.29493864  6.796610e-02 -1.183042e+04
## sex      -6.414267e-02   -0.01580172  2.138980e-04  1.518264e+03
## gmat_tot -5.891153e+00  -33.91633914 -2.499933e+00 -1.611600e+05
## gmat_qpc  6.001979e-01  -11.37186171  6.646346e-01 -3.335823e+04
## gmat_vpc -3.267667e+00   -3.61816529 -2.114569e+00 -5.273852e+03
## gmat_tpc -1.292372e+00   -7.85751718 -4.663244e-01  3.522750e+03
## s_avg    -3.223721e-01    0.15926392 -1.671372e-02  2.831601e+03
## f_avg    -2.608088e-01   -0.06628700 -6.260260e-03  7.876560e+02
## quarter   1.232119e+00   -0.30866822  3.553381e-02 -9.296214e+03
## work_yrs -3.086682e-01   10.44882490 -2.898318e-02  1.486147e+03
## frstlang  3.553381e-02   -0.02898318  1.035266e-01 -1.419586e+03
## salary   -9.296214e+03 1486.14704152 -1.419586e+03  2.596062e+09
## satis    -5.227133e-03 -131.24080907  9.484532e+00 -6.347115e+06
##                  satis
## age      -1.763499e+02
## sex      -8.780808e+00
## gmat_tot  1.765263e+03
## gmat_qpc  3.348371e+02
## gmat_vpc  3.923563e+02
## gmat_tpc  4.842467e+02
## s_avg    -4.628845e+00
## f_avg     2.125329e+00
## quarter  -5.227133e-03
## work_yrs -1.312408e+02
## frstlang  9.484532e+00
## salary   -6.347115e+06
## satis     1.380974e+05

creating a dataset of the students who actually got the job

mba1=mba[which(mba$salary!=0),]
View(mba1)

contigency

table(mba1$salary,mba1$satis)
##         
##           1  2  3  4  5  6  7 998
##   998     0  0  0  0  0  0  0  46
##   999     1  1  4 12  9  7  1   0
##   64000   0  0  0  0  0  0  1   0
##   77000   0  0  0  0  0  1  0   0
##   78256   0  0  0  0  1  0  0   0
##   82000   0  0  0  0  0  0  1   0
##   85000   0  0  0  0  1  3  0   0
##   86000   0  0  0  0  2  0  0   0
##   88000   0  0  0  0  0  0  1   0
##   88500   0  0  0  0  0  1  0   0
##   90000   0  0  0  0  2  0  1   0
##   92000   0  0  0  0  1  1  1   0
##   93000   0  0  0  0  1  2  0   0
##   95000   0  0  1  1  1  2  2   0
##   96000   0  0  0  0  1  1  2   0
##   96500   0  0  0  0  0  1  0   0
##   97000   0  0  0  0  0  1  1   0
##   98000   0  0  0  0  2  5  3   0
##   99000   0  0  0  0  0  1  0   0
##   100000  0  0  0  0  1  6  2   0
##   100400  0  0  0  0  0  0  1   0
##   101000  0  0  0  0  1  1  0   0
##   101100  0  0  0  0  0  1  0   0
##   101600  0  0  0  0  0  1  0   0
##   102500  0  0  0  0  1  0  0   0
##   103000  0  0  0  0  0  1  0   0
##   104000  0  0  0  0  1  1  0   0
##   105000  0  0  0  0  4  6  1   0
##   106000  0  0  0  0  0  2  1   0
##   107000  0  0  0  0  1  0  0   0
##   107300  0  0  0  0  0  0  1   0
##   107500  0  0  0  0  1  0  0   0
##   108000  0  0  0  0  0  2  0   0
##   110000  0  0  0  0  1  0  0   0
##   112000  0  0  0  0  0  2  1   0
##   115000  0  0  0  0  3  2  0   0
##   118000  0  0  0  0  0  0  1   0
##   120000  0  0  0  0  2  2  0   0
##   126710  0  0  0  0  0  1  0   0
##   130000  0  0  0  0  0  0  1   0
##   145800  0  0  0  0  0  1  0   0
##   146000  0  0  0  0  0  1  0   0
##   162000  0  0  0  0  1  0  0   0
##   220000  0  0  0  0  0  1  0   0
table(mba1$s_avg,mba1$f_avg)
##       
##        0 2 2.25 2.33 2.5 2.67 2.75 2.8 2.83 3 3.17 3.2 3.25 3.33 3.4 3.5
##   2.2  0 1    0    0   0    0    0   0    0 1    0   0    0    0   0   0
##   2.3  0 0    1    0   1    0    0   0    0 0    0   0    0    0   0   0
##   2.4  0 1    1    0   2    0    3   0    0 0    0   0    0    0   0   0
##   2.45 0 0    0    0   0    0    1   0    0 0    0   0    0    0   0   0
##   2.5  0 0    1    0   3    0    4   0    0 2    0   0    0    0   0   0
##   2.6  0 0    0    0   4    0    3   0    0 3    0   0    0    0   0   0
##   2.67 1 0    0    0   0    0    0   0    0 0    0   0    0    0   0   0
##   2.7  0 0    0    0   3    0    6   0    0 6    0   1    3    0   0   0
##   2.73 0 0    0    0   0    0    0   0    0 0    1   0    0    0   0   0
##   2.8  0 0    0    0   0    0    3   0    0 5    0   0    2    0   0   0
##   2.9  0 0    0    0   0    0    5   1    0 6    0   0    6    1   0   1
##   2.91 0 0    0    0   0    0    0   0    1 0    0   0    0    0   0   0
##   3    0 0    0    0   0    0    4   0    0 6    0   0    4    0   0   0
##   3.09 0 0    0    0   0    0    0   0    0 1    0   0    0    0   0   1
##   3.1  0 0    0    1   0    1    0   0    0 5    0   0    2    1   0   3
##   3.18 0 0    0    0   0    0    0   0    0 0    0   0    1    0   0   0
##   3.2  0 0    0    0   0    0    0   0    0 4    0   0    6    0   1   1
##   3.27 0 0    0    0   0    0    0   0    0 0    0   0    1    0   0   0
##   3.3  0 0    0    0   0    0    0   0    0 2    0   0    9    0   0   5
##   3.4  0 0    0    0   0    0    0   1    0 1    0   0    3    0   0   0
##   3.45 0 0    0    0   0    0    0   0    0 0    0   0    0    0   0   1
##   3.5  0 0    0    0   0    1    0   0    0 2    0   0    3    0   0   4
##   3.56 0 0    0    0   0    0    0   0    0 0    0   0    0    0   0   0
##   3.6  0 0    0    0   0    0    0   0    0 0    0   0    0    0   0   4
##   3.7  0 0    0    0   0    0    0   0    0 0    0   0    0    0   0   0
##   3.8  0 0    0    0   0    0    0   0    0 0    0   0    0    0   0   2
##   4    1 0    0    0   0    0    0   0    0 0    0   0    0    0   0   0
##       
##        3.6 3.67 3.75 4
##   2.2    0    0    0 0
##   2.3    0    0    0 0
##   2.4    0    0    0 0
##   2.45   0    0    0 0
##   2.5    0    0    0 0
##   2.6    0    0    0 0
##   2.67   0    0    0 0
##   2.7    0    0    0 0
##   2.73   0    0    0 0
##   2.8    0    0    0 0
##   2.9    0    0    0 0
##   2.91   0    0    0 0
##   3      0    0    0 0
##   3.09   0    0    0 0
##   3.1    0    0    1 0
##   3.18   0    0    0 0
##   3.2    0    0    0 0
##   3.27   0    0    0 0
##   3.3    0    0    0 0
##   3.4    0    1    2 1
##   3.45   0    1    0 0
##   3.5    1    0    1 2
##   3.56   0    0    0 1
##   3.6    0    1    2 0
##   3.7    1    0    0 1
##   3.8    0    0    0 1
##   4      0    0    0 1
table(mba1$gmat_tot,mba1$gmat_qpc)
##      
##       39 43 46 48 49 50 52 53 55 56 57 60 64 65 66 67 68 71 72 74 75 77 78
##   450  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   460  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0
##   500  0  0  1  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  1
##   520  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   530  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0
##   540  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0
##   550  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  2  1  0  0  0
##   560  1  0  0  0  0  0  3  0  1  0  1  1  1  0  0  0  1  0  0  0  1  0  0
##   570  0  0  0  0  0  0  0  0  0  1  0  0  0  1  0  0  1  1  1  0  1  0  0
##   580  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  3  0  0  0  1
##   590  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  2  0  1  0  0  0  0
##   600  0  0  0  0  0  0  0  1  0  0  0  1  0  0  0  1  1  0  1  0  0  4  0
##   610  0  0  0  1  0  0  0  0  0  0  0  0  1  0  0  0  0  0  1  0  1  0  0
##   620  0  0  0  0  0  0  1  0  0  0  0  1  0  0  0  0  0  0  1  0  0  0  1
##   630  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  2  0  1  0  0
##   640  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0
##   650  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   660  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0
##   670  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   680  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   690  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   700  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   710  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   720  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   730  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   740  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   790  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##      
##       79 81 82 83 84 85 87 88 89 90 91 92 93 94 95 96 97 98 99
##   450  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   460  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   500  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   520  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   530  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   540  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   550  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   560  1  1  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0
##   570  0  0  2  0  0  0  0  0  1  0  0  0  1  0  1  0  0  0  0
##   580  2  0  0  2  0  0  0  0  1  0  1  0  0  0  0  0  0  0  0
##   590  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  1  0  0
##   600  0  0  1  0  1  0  1  0  2  0  1  0  0  0  0  0  1  0  1
##   610  0  0  1  1  0  0  1  0  2  0  0  0  0  0  0  0  0  0  0
##   620  1  1  1  0  1  1  1  1  2  0  0  0  1  0  0  0  2  0  0
##   630  3  0  1  2  1  1  2  0  0  0  0  0  2  0  0  1  0  0  0
##   640  2  0  0  0  0  0  1  0  1  0  0  0  1  0  0  0  0  0  0
##   650  2  0  1  0  0  0  1  0  3  0  1  0  1  0  1  0  0  0  1
##   660  0  1  0  1  1  0  0  1  0  1  1  0  0  0  2  0  1  0  1
##   670  0  0  0  3  1  0  2  0  0  0  1  0  0  0  1  0  2  1  2
##   680  1  0  0  0  1  0  1  0  0  0  1  1  0  0  0  2  1  0  1
##   690  0  0  0  0  0  0  1  0  0  0  0  0  0  1  0  1  0  0  1
##   700  0  0  0  0  0  0  0  0  0  0  0  0  0  1  1  0  0  1  0
##   710  0  0  0  0  0  0  0  0  0  0  0  0  2  0  2  1  0  0  1
##   720  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  1  0  0
##   730  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0
##   740  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  3
##   790  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1
table(mba1$gmat_vpc,mba1$gmat_tpc)
##     
##      0 37 44 51 52 58 61 62 65 68 69 71 72 73 75 77 78 79 80 81 83 84 85
##   16 0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   22 0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   30 0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   33 0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0
##   37 0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0
##   41 0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  1  0  0  0
##   45 0  0  0  1  0  0  0  1  1  0  1  0  1  0  0  0  0  0  0  0  1  0  0
##   46 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   50 0  0  0  0  0  0  0  0  0  1  0  1  0  0  0  0  0  0  1  0  0  0  0
##   54 0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0
##   58 0  0  0  0  0  0  0  0  0  0  2  0  2  0  2  0  0  1  0  1  1  0  0
##   62 0  0  0  0  0  0  1  0  1  0  0  0  0  0  1  0  0  0  0  0  2  0  0
##   63 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   67 0  0  0  0  0  1  0  0  0  0  0  0  1  0  0  0  0  1  1  0  1  0  1
##   71 1  0  0  0  0  0  0  0  0  0  0  0  2  0  1  0  5  0  0  0  0  0  0
##   74 0  0  0  0  0  0  0  0  0  0  0  0  0  1  1  0  0  0  0  0  1  0  0
##   75 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   78 0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  2  0
##   81 0  0  0  0  0  0  0  0  0  0  0  0  3  0  0  0  1  0  0  2  1  2  0
##   82 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0
##   84 0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  1  1  0  0
##   85 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   87 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0
##   89 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0
##   90 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   91 0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  1  0  0
##   92 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   93 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   95 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0
##   96 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   97 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   98 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   99 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##     
##      86 87 88 89 90 91 92 93 94 95 96 97 98 99
##   16  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   22  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   30  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   33  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   37  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   41  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   45  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   46  1  0  0  0  0  0  0  0  0  0  0  0  0  0
##   50  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   54  0  1  0  0  0  0  0  0  0  0  0  0  0  0
##   58  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   62  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   63  0  0  1  0  0  0  0  1  0  0  0  0  0  0
##   67  1  0  0  0  0  0  0  0  0  0  0  0  0  0
##   71  1  1  0  1  0  1  0  0  0  1  0  0  0  0
##   74  0  5  0  0  0  0  0  0  0  0  1  0  0  0
##   75  0  0  0  0  0  1  0  0  0  0  0  0  0  0
##   78  0  0  0  0  0  1  0  0  0  0  0  0  0  0
##   81  2  1  0  0  1  1  0  1  1  2  2  0  0  0
##   82  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   84  1  1  0  2  0  1  0  3  1  0  0  0  0  0
##   85  0  0  0  1  0  0  0  0  0  0  2  0  0  0
##   87  1  0  1  4  1  0  0  1  0  0  1  2  0  0
##   89  0  1  0  1  1  0  0  1  0  1  0  1  0  0
##   90  0  0  0  0  0  0  0  0  0  1  0  1  0  0
##   91  0  0  0  2  0  0  0  2  0  0  0  0  0  0
##   92  0  0  0  0  0  0  1  0  1  0  0  0  0  1
##   93  1  0  0  1  0  1  0  1  2  1  0  1  1  0
##   95  0  0  0  2  0  1  0  1  1  2  0  1  3  0
##   96  0  1  0  0  0  0  0  0  0  1  2  0  1  0
##   97  0  0  0  0  0  0  0  0  0  0  1  0  0  1
##   98  1  1  0  0  0  0  1  0  0  1  2  0  4  5
##   99  0  0  0  0  0  0  0  0  0  1  1  0  0  2

chisquare test

chisq.test(mba1$salary,mba1$satis)
## Warning in chisq.test(mba1$salary, mba1$satis): Chi-squared approximation
## may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mba1$salary and mba1$satis
## X-squared = 391.04, df = 301, p-value = 0.0003578
chisq.test(mba1$s_avg,mba1$f_avg)
## Warning in chisq.test(mba1$s_avg, mba1$f_avg): Chi-squared approximation
## may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mba1$s_avg and mba1$f_avg
## X-squared = 1033.1, df = 494, p-value < 2.2e-16
chisq.test(mba1$gmat_tot,mba1$gmat_qpc)
## Warning in chisq.test(mba1$gmat_tot, mba1$gmat_qpc): Chi-squared
## approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mba1$gmat_tot and mba1$gmat_qpc
## X-squared = 1559.3, df = 1066, p-value < 2.2e-16
chisq.test(mba1$gmat_vpc,mba1$gmat_tpc)
## Warning in chisq.test(mba1$gmat_vpc, mba1$gmat_tpc): Chi-squared
## approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mba1$gmat_vpc and mba1$gmat_tpc
## X-squared = 1790.8, df = 1152, p-value < 2.2e-16
t.test(mba1$s_avg,mba1$f_avg)
## 
##  Welch Two Sample t-test
## 
## data:  mba1$s_avg and mba1$f_avg
## t = -0.81877, df = 339.4, p-value = 0.4135
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  -0.13110158  0.05403637
## sample estimates:
## mean of x mean of y 
##  3.022554  3.061087
t.test(mba1$s_avg,mba1$f_avg)
## 
##  Welch Two Sample t-test
## 
## data:  mba1$s_avg and mba1$f_avg
## t = -0.81877, df = 339.4, p-value = 0.4135
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  -0.13110158  0.05403637
## sample estimates:
## mean of x mean of y 
##  3.022554  3.061087
t.test(mba1$s_avg,mba1$f_avg)
## 
##  Welch Two Sample t-test
## 
## data:  mba1$s_avg and mba1$f_avg
## t = -0.81877, df = 339.4, p-value = 0.4135
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  -0.13110158  0.05403637
## sample estimates:
## mean of x mean of y 
##  3.022554  3.061087
t.test(mba1$s_avg,mba1$f_avg)
## 
##  Welch Two Sample t-test
## 
## data:  mba1$s_avg and mba1$f_avg
## t = -0.81877, df = 339.4, p-value = 0.4135
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  -0.13110158  0.05403637
## sample estimates:
## mean of x mean of y 
##  3.022554  3.061087

regression model

y=B0+B1gmattot+B2gmat_qpc y=B0+B1gmat_vpc+B2gmat_tpc

summ=lm(mba1$salary~mba1$gmat_tot+mba1$gmat_qpc)
summ
## 
## Call:
## lm(formula = mba1$salary ~ mba1$gmat_tot + mba1$gmat_qpc)
## 
## Coefficients:
##   (Intercept)  mba1$gmat_tot  mba1$gmat_qpc  
##     130669.17         -72.77        -334.92
summary(summ)$r.squared
## [1] 0.02226087
summ1=lm(mba1$salary~mba1$gmat_vpc+mba1$gmat_tpc)
summ1
## 
## Call:
## lm(formula = mba1$salary ~ mba1$gmat_vpc + mba1$gmat_tpc)
## 
## Coefficients:
##   (Intercept)  mba1$gmat_vpc  mba1$gmat_tpc  
##       83185.4          117.6         -403.2
summary(summ1)$r.squared
## [1] 0.006031796

From the value of r square, model of regression gmat_total & gmat_qpc is better. Meaning score in Gmat influence starting salary better.

Other Subset

mba2=mba[which(mba$salary==0),]
View(mba2)

contigency

table(mba2$salary,mba2$satis)
##    
##      4  5  6  7
##   0  4 36 40 10
table(mba2$s_avg,mba2$f_avg)
##       
##        0 2 2.25 2.5 2.67 2.75 3 3.17 3.2 3.25 3.33 3.4 3.5 3.6 3.67 3.75
##   2    0 1    0   0    0    0 0    0   0    0    0   0   0   0    0    0
##   2.1  0 1    0   1    0    0 0    0   0    0    0   0   0   0    0    0
##   2.2  0 0    1   0    0    0 0    0   0    0    0   0   0   0    0    0
##   2.3  0 0    1   1    0    0 0    0   0    0    0   0   0   0    0    0
##   2.4  0 0    0   1    0    1 0    0   0    0    0   0   0   0    0    0
##   2.6  0 1    0   0    0    0 0    0   0    0    0   0   0   0    0    0
##   2.7  0 0    0   2    0    3 2    0   0    1    0   0   0   0    0    0
##   2.8  0 0    0   1    0    2 4    0   0    2    0   0   0   0    0    0
##   2.82 0 0    0   1    0    0 0    0   0    0    0   0   0   0    0    0
##   2.9  0 0    0   0    0    1 4    0   0    4    0   0   0   0    0    0
##   3    0 0    0   1    0    1 5    0   1    2    0   0   0   0    0    0
##   3.08 0 0    0   0    0    0 0    0   0    1    0   0   0   0    0    0
##   3.09 0 0    0   0    0    0 0    1   0    0    0   0   1   0    0    0
##   3.1  0 0    0   0    0    0 3    0   0    1    0   0   1   0    1    0
##   3.17 0 0    0   0    0    0 0    0   0    0    0   0   1   0    0    0
##   3.2  0 0    0   0    0    0 2    0   0    2    0   0   0   0    0    0
##   3.25 1 0    0   0    0    0 0    0   0    0    0   0   0   0    0    0
##   3.27 0 0    0   0    0    0 0    0   0    0    0   1   0   0    0    1
##   3.3  0 0    0   0    1    1 1    0   0    3    0   0   0   0    0    2
##   3.38 0 0    0   0    0    0 1    0   0    0    0   0   0   0    0    0
##   3.4  0 0    0   0    0    0 2    0   0    1    0   0   3   0    0    1
##   3.45 0 0    0   0    0    0 0    0   0    0    0   0   0   0    0    0
##   3.5  0 0    0   0    0    0 0    0   0    0    0   0   1   0    0    0
##   3.6  0 0    0   0    0    0 0    0   0    1    0   0   0   1    0    1
##   3.64 0 0    0   0    0    0 0    0   0    0    1   0   0   0    0    0
##   3.8  0 0    0   0    0    0 0    0   0    0    0   0   0   0    0    0
##   3.9  0 0    0   0    0    0 0    0   0    0    0   0   0   0    0    1
##       
##        3.83 4
##   2       0 0
##   2.1     0 0
##   2.2     0 0
##   2.3     0 0
##   2.4     0 0
##   2.6     0 0
##   2.7     0 0
##   2.8     0 0
##   2.82    0 0
##   2.9     0 0
##   3       0 0
##   3.08    0 0
##   3.09    0 0
##   3.1     0 0
##   3.17    0 0
##   3.2     0 0
##   3.25    0 0
##   3.27    0 0
##   3.3     0 1
##   3.38    0 0
##   3.4     0 0
##   3.45    1 0
##   3.5     0 1
##   3.6     0 1
##   3.64    0 0
##   3.8     0 1
##   3.9     0 0
table(mba2$gmat_tot,mba2$gmat_qpc)
##      
##       28 35 43 48 49 52 56 57 59 60 61 64 66 68 69 72 73 74 75 77 79 81 82
##   450  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   480  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   510  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0
##   530  0  1  0  1  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0
##   540  0  0  1  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0
##   550  0  0  0  0  0  1  0  0  0  0  0  0  1  0  0  1  1  0  0  0  0  0  0
##   560  0  0  1  0  0  0  1  0  1  1  1  1  0  0  0  0  0  1  0  0  0  0  0
##   570  0  0  0  1  0  0  1  0  0  0  1  0  0  0  1  1  0  0  1  0  0  0  1
##   580  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  1  0  0  1  0  0
##   590  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0
##   600  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0
##   610  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  1  0  2
##   620  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  1  0  1  1
##   630  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  2
##   640  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  1
##   650  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0
##   660  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   670  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   680  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   700  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   710  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   720  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   730  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   740  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   750  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   760  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##      
##       84 85 87 88 89 90 91 92 93 94 95 96 97 98 99
##   450  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   480  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   510  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   530  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   540  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   550  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   560  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0
##   570  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   580  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   590  1  0  0  0  0  0  0  1  0  0  0  0  0  0  0
##   600  0  0  0  0  1  0  0  0  0  0  1  0  0  0  0
##   610  0  1  0  0  1  1  1  0  0  0  0  0  1  0  0
##   620  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   630  0  0  0  0  0  0  0  0  1  0  0  0  0  0  1
##   640  0  0  0  0  1  1  0  0  0  1  0  1  0  0  0
##   650  0  0  1  2  1  0  0  0  0  0  0  0  0  0  0
##   660  0  0  0  0  0  0  0  0  1  2  0  0  0  0  0
##   670  0  0  0  0  1  0  1  0  0  1  0  0  0  0  1
##   680  0  0  0  0  1  0  0  0  0  1  0  0  1  0  0
##   700  0  0  0  0  1  0  0  0  0  0  0  0  0  0  1
##   710  0  0  0  0  0  0  0  0  0  1  0  1  1  0  1
##   720  0  0  0  0  0  0  0  0  0  0  1  0  0  0  1
##   730  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0
##   740  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1
##   750  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1
##   760  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1
table(mba2$gmat_vpc,mba2$gmat_tpc)
##     
##      0 34 45 54 55 62 65 69 71 72 73 75 76 78 81 83 86 87 89 90 91 92 93
##   22 0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   41 0  0  1  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0
##   45 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0
##   46 0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   50 0  0  0  0  1  0  1  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0
##   54 0  0  0  0  0  1  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0
##   58 0  0  0  0  0  0  0  1  0  0  0  1  0  1  1  0  0  0  0  0  0  0  0
##   62 0  0  0  0  0  0  0  0  0  0  0  1  0  0  1  1  1  0  0  0  0  0  0
##   63 0  0  0  0  0  0  0  2  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   67 0  0  0  0  0  0  0  0  0  0  1  0  0  1  0  0  0  0  0  0  0  0  0
##   70 0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0
##   71 1  0  0  0  0  1  1  0  0  1  0  1  0  0  0  0  0  1  0  0  1  0  0
##   74 0  0  0  0  0  0  0  0  0  0  2  0  0  0  0  0  0  1  0  0  0  0  0
##   78 0  0  0  0  0  0  1  0  1  1  0  0  0  0  0  1  2  0  0  0  1  1  0
##   81 0  0  0  0  0  1  0  0  0  1  0  1  1  0  0  0  2  0  0  0  0  0  0
##   84 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  1  1
##   87 0  0  0  0  0  0  0  0  0  1  0  0  0  1  1  0  0  1  1  0  0  1  0
##   89 0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0  1  1  1  0  1  1  1
##   90 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0
##   91 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0
##   92 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1
##   95 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0  0
##   96 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   97 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##   98 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1
##   99 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0
##     
##      94 95 96 97 98 99
##   22  0  0  0  0  0  0
##   41  0  0  0  0  0  0
##   45  0  0  0  0  0  0
##   46  0  0  0  0  0  0
##   50  0  0  0  0  0  0
##   54  0  0  0  0  0  0
##   58  0  0  0  0  0  0
##   62  0  0  0  0  0  0
##   63  0  0  0  0  0  0
##   67  0  0  0  0  0  0
##   70  0  0  0  0  0  0
##   71  0  0  0  0  0  0
##   74  0  0  0  0  0  0
##   78  0  1  0  0  0  0
##   81  0  0  0  0  0  0
##   84  1  0  0  0  0  0
##   87  1  1  1  0  1  0
##   89  0  0  1  0  0  0
##   90  0  0  0  0  0  0
##   91  0  2  0  0  1  0
##   92  0  0  0  1  0  0
##   95  0  0  0  0  0  1
##   96  0  0  1  0  0  2
##   97  0  0  0  0  0  2
##   98  0  0  0  0  1  3
##   99  0  0  0  0  0  1

chi-square test

chisq.test(mba2$s_avg,mba2$f_avg)
## Warning in chisq.test(mba2$s_avg, mba2$f_avg): Chi-squared approximation
## may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mba2$s_avg and mba2$f_avg
## X-squared = 722.17, df = 442, p-value = 7.981e-16
chisq.test(mba2$gmat_tot,mba2$gmat_qpc)
## Warning in chisq.test(mba2$gmat_tot, mba2$gmat_qpc): Chi-squared
## approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mba2$gmat_tot and mba2$gmat_qpc
## X-squared = 986.48, df = 925, p-value = 0.07862
chisq.test(mba2$gmat_vpc,mba2$gmat_tpc)
## Warning in chisq.test(mba2$gmat_vpc, mba2$gmat_tpc): Chi-squared
## approximation may be incorrect
## 
##  Pearson's Chi-squared test
## 
## data:  mba2$gmat_vpc and mba2$gmat_tpc
## X-squared = 856.17, df = 700, p-value = 4.502e-05