The Dean’s Dilemma Case study

This is a case study based on the case “Dean’s Dilemma: Selection of Students for the MBA Program”.

Reading and Viewing the Dean’s Dilemma Database

setwd("C:\\Users\\Adithya Nataraj\\Downloads")
mba.df<-read.csv(paste("Data - Deans Dilemma.csv", sep=""))
View(mba.df)

Summary statistics of Dean’s Dilemma database

summary(mba.df)
##       SlNo       Gender     Gender.B       Percent_SSC     Board_SSC  
##  Min.   :  1.0   F:127   Min.   :0.0000   Min.   :37.00   CBSE  :113  
##  1st Qu.: 98.5   M:264   1st Qu.:0.0000   1st Qu.:56.00   ICSE  : 77  
##  Median :196.0           Median :0.0000   Median :64.50   Others:201  
##  Mean   :196.0           Mean   :0.3248   Mean   :64.65               
##  3rd Qu.:293.5           3rd Qu.:1.0000   3rd Qu.:74.00               
##  Max.   :391.0           Max.   :1.0000   Max.   :87.20               
##                                                                       
##    Board_CBSE      Board_ICSE      Percent_HSC    Board_HSC  
##  Min.   :0.000   Min.   :0.0000   Min.   :40.0   CBSE  : 96  
##  1st Qu.:0.000   1st Qu.:0.0000   1st Qu.:54.0   ISC   : 48  
##  Median :0.000   Median :0.0000   Median :63.0   Others:247  
##  Mean   :0.289   Mean   :0.1969   Mean   :63.8               
##  3rd Qu.:1.000   3rd Qu.:0.0000   3rd Qu.:72.0               
##  Max.   :1.000   Max.   :1.0000   Max.   :94.7               
##                                                              
##     Stream_HSC  Percent_Degree                Course_Degree
##  Arts    : 18   Min.   :35.00   Arts                 : 13  
##  Commerce:222   1st Qu.:57.52   Commerce             :117  
##  Science :151   Median :63.00   Computer Applications: 32  
##                 Mean   :62.98   Engineering          : 37  
##                 3rd Qu.:69.00   Management           :163  
##                 Max.   :89.00   Others               :  5  
##                                 Science              : 24  
##   Degree_Engg      Experience_Yrs   Entrance_Test     S.TEST      
##  Min.   :0.00000   Min.   :0.0000   MAT    :265   Min.   :0.0000  
##  1st Qu.:0.00000   1st Qu.:0.0000   None   : 67   1st Qu.:1.0000  
##  Median :0.00000   Median :0.0000   K-MAT  : 24   Median :1.0000  
##  Mean   :0.09463   Mean   :0.4783   CAT    : 22   Mean   :0.8286  
##  3rd Qu.:0.00000   3rd Qu.:1.0000   PGCET  :  8   3rd Qu.:1.0000  
##  Max.   :1.00000   Max.   :3.0000   GCET   :  2   Max.   :1.0000  
##                                     (Other):  3                   
##  Percentile_ET    S.TEST.SCORE    Percent_MBA   
##  Min.   : 0.00   Min.   : 0.00   Min.   :50.83  
##  1st Qu.:41.19   1st Qu.:41.19   1st Qu.:57.20  
##  Median :62.00   Median :62.00   Median :61.01  
##  Mean   :54.93   Mean   :54.93   Mean   :61.67  
##  3rd Qu.:78.00   3rd Qu.:78.00   3rd Qu.:66.02  
##  Max.   :98.69   Max.   :98.69   Max.   :77.89  
##                                                 
##            Specialization_MBA Marks_Communication Marks_Projectwork
##  Marketing & Finance:222      Min.   :50.00       Min.   :50.00    
##  Marketing & HR     :156      1st Qu.:53.00       1st Qu.:64.00    
##  Marketing & IB     : 13      Median :58.00       Median :69.00    
##                               Mean   :60.54       Mean   :68.36    
##                               3rd Qu.:67.00       3rd Qu.:74.00    
##                               Max.   :88.00       Max.   :87.00    
##                                                                    
##    Marks_BOCA         Placement    Placement_B        Salary      
##  Min.   :50.00   Not Placed: 79   Min.   :0.000   Min.   :     0  
##  1st Qu.:57.00   Placed    :312   1st Qu.:1.000   1st Qu.:172800  
##  Median :63.00                    Median :1.000   Median :240000  
##  Mean   :64.38                    Mean   :0.798   Mean   :219078  
##  3rd Qu.:72.50                    3rd Qu.:1.000   3rd Qu.:300000  
##  Max.   :96.00                    Max.   :1.000   Max.   :940000  
## 
library(psych)
describe(mba.df)
##                     vars   n      mean        sd    median   trimmed
## SlNo                   1 391    196.00    113.02    196.00    196.00
## Gender*                2 391      1.68      0.47      2.00      1.72
## Gender.B               3 391      0.32      0.47      0.00      0.28
## Percent_SSC            4 391     64.65     10.96     64.50     64.76
## Board_SSC*             5 391      2.23      0.87      3.00      2.28
## Board_CBSE             6 391      0.29      0.45      0.00      0.24
## Board_ICSE             7 391      0.20      0.40      0.00      0.12
## Percent_HSC            8 391     63.80     11.42     63.00     63.34
## Board_HSC*             9 391      2.39      0.85      3.00      2.48
## Stream_HSC*           10 391      2.34      0.56      2.00      2.36
## Percent_Degree        11 391     62.98      8.92     63.00     62.91
## Course_Degree*        12 391      3.85      1.61      4.00      3.81
## Degree_Engg           13 391      0.09      0.29      0.00      0.00
## Experience_Yrs        14 391      0.48      0.67      0.00      0.36
## Entrance_Test*        15 391      5.85      1.35      6.00      6.08
## S.TEST                16 391      0.83      0.38      1.00      0.91
## Percentile_ET         17 391     54.93     31.17     62.00     56.87
## S.TEST.SCORE          18 391     54.93     31.17     62.00     56.87
## Percent_MBA           19 391     61.67      5.85     61.01     61.45
## Specialization_MBA*   20 391      1.47      0.56      1.00      1.42
## Marks_Communication   21 391     60.54      8.82     58.00     59.68
## Marks_Projectwork     22 391     68.36      7.15     69.00     68.60
## Marks_BOCA            23 391     64.38      9.58     63.00     64.08
## Placement*            24 391      1.80      0.40      2.00      1.87
## Placement_B           25 391      0.80      0.40      1.00      0.87
## Salary                26 391 219078.26 138311.65 240000.00 217011.50
##                          mad   min       max     range  skew kurtosis
## SlNo                  145.29  1.00    391.00    390.00  0.00    -1.21
## Gender*                 0.00  1.00      2.00      1.00 -0.75    -1.45
## Gender.B                0.00  0.00      1.00      1.00  0.75    -1.45
## Percent_SSC            12.60 37.00     87.20     50.20 -0.06    -0.72
## Board_SSC*              0.00  1.00      3.00      2.00 -0.45    -1.53
## Board_CBSE              0.00  0.00      1.00      1.00  0.93    -1.14
## Board_ICSE              0.00  0.00      1.00      1.00  1.52     0.31
## Percent_HSC            13.34 40.00     94.70     54.70  0.29    -0.67
## Board_HSC*              0.00  1.00      3.00      2.00 -0.83    -1.13
## Stream_HSC*             0.00  1.00      3.00      2.00 -0.12    -0.72
## Percent_Degree          8.90 35.00     89.00     54.00  0.05     0.24
## Course_Degree*          1.48  1.00      7.00      6.00  0.00    -1.08
## Degree_Engg             0.00  0.00      1.00      1.00  2.76     5.63
## Experience_Yrs          0.00  0.00      3.00      3.00  1.27     1.17
## Entrance_Test*          0.00  1.00      9.00      8.00 -2.52     7.04
## S.TEST                  0.00  0.00      1.00      1.00 -1.74     1.02
## Percentile_ET          25.20  0.00     98.69     98.69 -0.74    -0.69
## S.TEST.SCORE           25.20  0.00     98.69     98.69 -0.74    -0.69
## Percent_MBA             6.39 50.83     77.89     27.06  0.34    -0.52
## Specialization_MBA*     0.00  1.00      3.00      2.00  0.70    -0.56
## Marks_Communication     8.90 50.00     88.00     38.00  0.74    -0.25
## Marks_Projectwork       7.41 50.00     87.00     37.00 -0.26    -0.27
## Marks_BOCA             11.86 50.00     96.00     46.00  0.29    -0.85
## Placement*              0.00  1.00      2.00      1.00 -1.48     0.19
## Placement_B             0.00  0.00      1.00      1.00 -1.48     0.19
## Salary              88956.00  0.00 940000.00 940000.00  0.24     1.74
##                          se
## SlNo                   5.72
## Gender*                0.02
## Gender.B               0.02
## Percent_SSC            0.55
## Board_SSC*             0.04
## Board_CBSE             0.02
## Board_ICSE             0.02
## Percent_HSC            0.58
## Board_HSC*             0.04
## Stream_HSC*            0.03
## Percent_Degree         0.45
## Course_Degree*         0.08
## Degree_Engg            0.01
## Experience_Yrs         0.03
## Entrance_Test*         0.07
## S.TEST                 0.02
## Percentile_ET          1.58
## S.TEST.SCORE           1.58
## Percent_MBA            0.30
## Specialization_MBA*    0.03
## Marks_Communication    0.45
## Marks_Projectwork      0.36
## Marks_BOCA             0.48
## Placement*             0.02
## Placement_B            0.02
## Salary              6994.72

There are 390 entries in total. The average salary of a student is 219078.26 rupees.

Answer to 3a: median salary of all the students

median(mba.df$Salary)
## [1] 240000

The median is 240000 rupees.

Answer to 3b: the percentage of students who were placed

mytable <- xtabs(~ Placement_B, data=mba.df)
mytable
## Placement_B
##   0   1 
##  79 312
format(round((prop.table(mytable)*100), 2), nsmall = 2)
## Placement_B
##       0       1 
## "20.20" "79.80"

79.80% of the students were placed.

Answer to 3c: Creating and viewing a dataframe called ‘placed’, that contains a subset of only those students who were successfully placed

placed.df <- subset(mba.df, mba.df$Placement_B==1 ) 
View(placed.df)

Answer to 3d: median salary of students who were placed

median(placed.df$Salary)
## [1] 260000

The median salary of students who were placed is 260000 rupees

Answer to 3e: table showing the mean salary of males and females, who were placed

placed.salary.mean <- aggregate(placed.df$Salary, list(placed.df$Gender), mean)
colnames(placed.salary.mean)[2] <- "Mean Salary"
colnames(placed.salary.mean)[1] <- "Gender"
placed.salary.mean
##   Gender Mean Salary
## 1      F    253068.0
## 2      M    284241.9

The mean salary of females who were placed is 253068.0 rupees and that of males who were placed is 284241.9 rupees

Answer to 3f: histogram showing MBA performance of the students who were placed

hist(placed.df$Percent_MBA, main="MBA Performance of placed students", ylab="Count", xlab="MBA Percentage", col=c("orange","red","black","green"), breaks=20, xlim=c(50,80), ylim=c(0,30))

From the graph, maximum number of students have got an average percentage of 62-63% during their mba.

Answer to 3g: Creating and viewing a dataframe called ‘notplaced’, that contains a set of only those students who were not placed after their MBA

notplaced.df <- subset(mba.df, mba.df$Placement_B==0 ) 
View(notplaced.df)

Answer to 3h: comparison of the MBA performance of Placed and Not Placed students

par(mfrow=c(1,2))
hist(placed.df$Percent_MBA, main="MBA Performance of placed students", ylab="Count", xlab="MBA Percentage", col="turquoise", breaks=20, xlim=c(50,80), ylim=c(0,30))
hist(notplaced.df$Percent_MBA, main="MBA Performance of NOT placed students", ylab="Count", xlab="MBA Percentage", col="turquoise", breaks=20, xlim=c(50,80), ylim=c(0,8))

From the graph, it is clear that the performance of the placed MBA students is just a bit better than that of not placed MBA students.

Answer to 3i: comparison of the distribution of salaries of males and females who were placed

boxplot(Salary ~ Gender, data=placed.df, yaxt="n", horizontal = TRUE, ylab="Gender", 
        xlab="Salary", main="Comparison of salaries of Males and Females", col=c("green", "red"))
axis(side=2, at=c(1,2), labels=c("Males" , "Females"))

From the boxplot, the females who are placed have higher salaries than males. The median salary of females are also higher than that of males who are placed.

Answer to 3j: Creating and viewing a dataframe called ‘placedet’, representing students who were placed after completing MBA and who also gave some MBA entrance test before admission into the MBA program

placedet.df <- subset(mba.df, mba.df$Placement_B==1 & mba.df$S.TEST==1) 
View(placedet.df)

Answer to 3k: Scatter Plot Matrix for 3 variables: salary, percentage obtained in mba program and percentile obtained in mba entrance test

library(car)
## 
## Attaching package: 'car'
## The following object is masked from 'package:psych':
## 
##     logit
scatterplotMatrix(formula= ~ Salary+Percent_MBA+Percentile_ET, cex=0.6, data=placedet.df, diagonal="density", main="Scatter Plot Matrix")

From the scatterplot, it is clear that students who have took an entrance test have performed better during their MBA program.