The RMD file contains the Data Analysis of “MBA Starting Salaries” case study.

Possible questions before joining the Particular B-School

Whether to enroll in the MBA program at this particular school? About starting salaries, whether gender and/or age made a difference? Whether students liked this particular program?? Whether her GMAT score made a difference in marks?

Primary Variables for salary variation

GMAT Score, Gender, Age, WorkExperience

More chances of Enrollment

Better Salary, More Satisfaction Rating

Reading the Data in to R

MBA_Data <- read.csv(paste("MBA Starting Salaries Data.csv",sep=""))
dim(MBA_Data)
## [1] 274  13
View(MBA_Data)

Creating summary statistics (e.g. mean, standard deviation, median, mode) for the important variables in the dataset.

library(psych)
describe(MBA_Data)
##          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

Structure of Data

str(MBA_Data)
## 'data.frame':    274 obs. of  13 variables:
##  $ age     : int  23 24 24 24 24 24 25 25 25 25 ...
##  $ sex     : int  2 1 1 1 2 1 1 2 1 1 ...
##  $ gmat_tot: int  620 610 670 570 710 640 610 650 630 680 ...
##  $ gmat_qpc: int  77 90 99 56 93 82 89 88 79 99 ...
##  $ gmat_vpc: int  87 71 78 81 98 89 74 89 91 81 ...
##  $ gmat_tpc: int  87 87 95 75 98 91 87 92 89 96 ...
##  $ s_avg   : num  3.4 3.5 3.3 3.3 3.6 3.9 3.4 3.3 3.3 3.45 ...
##  $ f_avg   : num  3 4 3.25 2.67 3.75 3.75 3.5 3.75 3.25 3.67 ...
##  $ quarter : int  1 1 1 1 1 1 1 1 1 1 ...
##  $ work_yrs: int  2 2 2 1 2 2 2 2 2 2 ...
##  $ frstlang: int  1 1 1 1 1 1 1 1 2 1 ...
##  $ salary  : int  0 0 0 0 999 0 0 0 999 998 ...
##  $ satis   : int  7 6 6 7 5 6 5 6 4 998 ...

Converting the data type of some columns

Sex

MBA_Data$sex[MBA_Data$sex==1] <- "Male"
MBA_Data$sex[MBA_Data$sex==2] <- "Female"
MBA_Data$sex= factor(MBA_Data$sex)

First Language

MBA_Data$frstlang[MBA_Data$frstlang==1] <- "English"
MBA_Data$frstlang[MBA_Data$frstlang==2] <- "Other"
MBA_Data$frstlang= factor(MBA_Data$frstlang)
str(MBA_Data)
## 'data.frame':    274 obs. of  13 variables:
##  $ age     : int  23 24 24 24 24 24 25 25 25 25 ...
##  $ sex     : Factor w/ 2 levels "Female","Male": 1 2 2 2 1 2 2 1 2 2 ...
##  $ gmat_tot: int  620 610 670 570 710 640 610 650 630 680 ...
##  $ gmat_qpc: int  77 90 99 56 93 82 89 88 79 99 ...
##  $ gmat_vpc: int  87 71 78 81 98 89 74 89 91 81 ...
##  $ gmat_tpc: int  87 87 95 75 98 91 87 92 89 96 ...
##  $ s_avg   : num  3.4 3.5 3.3 3.3 3.6 3.9 3.4 3.3 3.3 3.45 ...
##  $ f_avg   : num  3 4 3.25 2.67 3.75 3.75 3.5 3.75 3.25 3.67 ...
##  $ quarter : int  1 1 1 1 1 1 1 1 1 1 ...
##  $ work_yrs: int  2 2 2 1 2 2 2 2 2 2 ...
##  $ frstlang: Factor w/ 2 levels "English","Other": 1 1 1 1 1 1 1 1 2 1 ...
##  $ salary  : int  0 0 0 0 999 0 0 0 999 998 ...
##  $ satis   : int  7 6 6 7 5 6 5 6 4 998 ...

998 = did not answer the survey

999 = answered the survey but did not disclose salary data

0: Not Yet Placed

Salary Value = Who are Placed

DataFrame-1

NotAnsweredSurvey <- MBA_Data[which(MBA_Data$salary=='998'),]
NotAnsweredSurvey
##     age    sex gmat_tot gmat_qpc gmat_vpc gmat_tpc s_avg f_avg quarter
## 10   25   Male      680       99       81       96  3.45  3.67       1
## 11   26   Male      740       99       98       99  3.56  4.00       1
## 12   26 Female      610       75       87       86  3.40  3.75       1
## 13   26   Male      710       95       95       98  3.50  3.50       1
## 14   26   Male      720       97       97       99  3.40  4.00       1
## 15   26 Female      660       84       93       94  3.30  3.25       1
## 16   26 Female      640       67       98       92  4.00  4.00       1
## 17   27 Female      660       71       99       95  3.50  4.00       1
## 18   27   Male      600       77       78       84  3.30  3.50       1
## 19   27   Male      630       79       89       89  3.50  4.00       1
## 20   27   Male      600       91       58       83  3.40  3.25       1
## 79   25 Female      670       99       85       96  3.00  3.25       2
## 80   25   Male      690       94       95       98  3.00  2.75       2
## 81   25 Female      630       83       89       90  3.00  2.75       2
## 82   25   Male      670       99       74       96  3.18  3.25       2
## 83   25   Male      680       91       95       97  3.00  3.00       2
## 84   25   Male      690       96       89       97  3.00  3.00       2
## 85   25   Male      670       97       81       95  3.10  3.25       2
## 86   25   Male      580       79       71       78  3.10  2.33       2
## 94   27   Male      630       87       84       89  3.20  3.00       2
## 95   27   Male      560       60       71       72  3.20  3.00       2
## 96   28 Female      450       49       22       44  3.10  3.75       2
## 148  25   Male      600       89       62       83  2.70  3.25       3
## 149  25   Male      630       79       91       89  2.70  2.75       3
## 153  25   Male      630       93       71       89  2.90  3.25       3
## 154  25   Male      560       79       58       72  2.73  3.17       3
## 155  26   Male      670       97       81       96  2.70  2.50       3
## 156  26   Male      660       88       93       94  2.90  2.75       3
## 157  26   Male      630       83       87       90  2.70  3.00       3
## 171  27   Male      600       68       87       83  2.90  3.25       3
## 172  27   Male      650       79       95       93  2.70  3.25       3
## 173  27   Male      560       52       81       72  2.70  2.75       3
## 174  27   Male      610       48       98       86  2.70  3.00       3
## 175  27   Male      600       77       81       84  2.70  3.00       3
## 176  28   Male      460       66       16       37  2.70  2.50       3
## 177  28   Male      650       99       63       93  2.90  3.00       3
## 178  28 Female      610       64       93       86  2.80  3.25       3
## 210  24   Male      610       82       81       86  2.50  2.75       4
## 211  24   Male      640       93       78       91  2.40  2.50       4
## 215  25   Male      640       79       93       91  2.67  0.00       4
## 216  25   Male      590       68       81       81  2.60  2.75       4
## 224  26   Male      590       89       58       81  2.50  2.25       4
## 225  26 Female      670       98       81       95  2.60  2.50       4
## 247  30   Male      630       82       87       89  3.80  3.50       4
## 248  31   Male      580       83       67       79  3.00  3.25       4
## 249  31   Male      740       99       98       99  2.20  3.00       4
##     work_yrs frstlang salary satis
## 10         2  English    998   998
## 11         2  English    998   998
## 12         2  English    998   998
## 13         3  English    998   998
## 14         2  English    998   998
## 15         4  English    998   998
## 16         2  English    998   998
## 17         4  English    998   998
## 18         3    Other    998   998
## 19         2  English    998   998
## 20         4  English    998   998
## 79         2    Other    998   998
## 80         2  English    998   998
## 81         3  English    998   998
## 82         2    Other    998   998
## 83         2  English    998   998
## 84         3  English    998   998
## 85         2  English    998   998
## 86         2  English    998   998
## 94         4  English    998   998
## 95         4  English    998   998
## 96         4    Other    998   998
## 148        4  English    998   998
## 149        2  English    998   998
## 153        3    Other    998   998
## 154        2    Other    998   998
## 155        4  English    998   998
## 156        3    Other    998   998
## 157        3  English    998   998
## 171        3  English    998   998
## 172        3  English    998   998
## 173        2  English    998   998
## 174        4  English    998   998
## 175        3  English    998   998
## 176        4  English    998   998
## 177        4    Other    998   998
## 178        4  English    998   998
## 210        2  English    998   998
## 211        1  English    998   998
## 215        1  English    998   998
## 216        3  English    998   998
## 224        3  English    998   998
## 225        3  English    998   998
## 247        7  English    998   998
## 248        6  English    998   998
## 249        8  English    998   998

DataFrame-2

NotdisclosedSalary <- MBA_Data[which(MBA_Data$salary=='999'),]
NotdisclosedSalary
##     age    sex gmat_tot gmat_qpc gmat_vpc gmat_tpc s_avg f_avg quarter
## 5    24 Female      710       93       98       98  3.60  3.75       1
## 9    25   Male      630       79       91       89  3.30  3.25       1
## 21   27 Female      570       65       82       77  3.30  3.25       1
## 26   30   Male      620       82       84       87  3.40  2.80       1
## 30   32   Male      570       71       71        0  3.50  3.50       1
## 78   25   Male      690       87       98       98  3.00  3.00       2
## 87   26   Male      680       92       93       97  3.00  3.00       2
## 91   27   Male      740       99       98       99  3.10  3.50       2
## 99   28   Male      660       95       85       96  3.10  3.25       2
## 101  29   Male      580       91       50       80  3.10  2.67       2
## 105  29   Male      590       68       84       81  3.10  3.00       2
## 108  31   Male      670       83       98       96  3.20  3.40       2
## 145  24   Male      650       89       84       93  2.70  3.25       3
## 152  25   Male      660       95       84       94  2.70  3.00       3
## 158  26   Male      640       87       84       91  2.70  3.20       3
## 161  26   Male      600       97       45       83  2.70  3.00       3
## 166  27   Male      730       95       99       99  2.90  3.33       3
## 170  27 Female      620       97       54       87  2.70  2.75       3
## 179  28   Male      500       46       54       52  2.90  2.75       3
## 181  29   Male      560       57       74       73  2.80  3.00       3
## 212  25   Male      600       53       95       84  2.50  3.00       4
## 214  25 Female      650       87       91       93  2.50  2.50       4
## 217  25   Male      590       97       41       81  2.50  2.75       4
## 221  26   Male      560       87       45       72  2.60  3.00       4
## 223  26   Male      570       82       58       75  2.50  2.75       4
## 226  27   Male      660       97       81       94  2.50  2.50       4
## 228  27   Male      790       99       99       99  2.40  2.50       4
## 231  27   Male      620       85       85       89  3.30  3.00       4
## 235  28   Male      620       93       71       87  2.40  2.75       4
## 239  29   Male      690       99       87       97  2.30  2.25       4
## 240  29   Male      630       87       84       89  2.90  2.80       4
## 245  30   Male      550       79       45       69  2.45  2.75       4
## 246  30 Female      600       99       46       86  2.80  3.00       4
## 251  31   Male      640       79       92       92  2.70  2.75       4
## 252  32   Male      570       89       41       75  2.60  2.50       4
##     work_yrs frstlang salary satis
## 5          2  English    999     5
## 9          2    Other    999     4
## 21         4  English    999     4
## 26         5  English    999     6
## 30         4  English    999     4
## 78         3  English    999     5
## 87         3  English    999     1
## 91         2  English    999     4
## 99         4  English    999     3
## 101        4    Other    999     4
## 105        6  English    999     5
## 108        4  English    999     6
## 145        1  English    999     5
## 152        3  English    999     6
## 158        4  English    999     5
## 161        4    Other    999     6
## 166        0  English    999     5
## 170        2    Other    999     2
## 179        9  English    999     6
## 181        4  English    999     5
## 212        2  English    999     4
## 214        3  English    999     7
## 217        2    Other    999     4
## 221        3    Other    999     3
## 223        3  English    999     6
## 226        4  English    999     4
## 228        4  English    999     6
## 231        1  English    999     5
## 235        3  English    999     4
## 239        7  English    999     5
## 240        3  English    999     4
## 245        5    Other    999     4
## 246        6    Other    999     4
## 251        7  English    999     3
## 252        4    Other    999     3

DataFrame-3

NotPlaced <- MBA_Data[which(MBA_Data$salary=='0'),]
NotPlaced
##     age    sex gmat_tot gmat_qpc gmat_vpc gmat_tpc s_avg f_avg quarter
## 1    23 Female      620       77       87       87  3.40  3.00       1
## 2    24   Male      610       90       71       87  3.50  4.00       1
## 3    24   Male      670       99       78       95  3.30  3.25       1
## 4    24   Male      570       56       81       75  3.30  2.67       1
## 6    24   Male      640       82       89       91  3.90  3.75       1
## 7    25   Male      610       89       74       87  3.40  3.50       1
## 8    25 Female      650       88       89       92  3.30  3.75       1
## 22   27   Male      740       99       96       99  3.50  3.50       1
## 23   27   Male      750       99       98       99  3.40  3.50       1
## 24   28 Female      540       75       50       65  3.60  4.00       1
## 25   29   Male      580       56       87       78  3.64  3.33       1
## 27   31 Female      560       60       78       72  3.30  3.75       1
## 28   32   Male      760       99       99       99  3.40  3.00       1
## 29   32   Male      640       79       91       91  3.60  3.75       1
## 31   34 Female      620       75       89       87  3.30  3.00       1
## 32   37 Female      560       43       87       72  3.40  3.50       1
## 33   42 Female      650       75       98       93  3.38  3.00       1
## 34   48   Male      590       84       62       81  3.80  4.00       1
## 70   22   Male      600       95       54       83  3.00  3.00       2
## 71   23   Male      640       89       87       92  3.00  3.00       2
## 72   24   Male      550       73       63       69  3.10  3.00       2
## 73   24   Male      570       82       58       75  3.09  3.50       2
## 74   24   Male      620       82       84       87  3.10  3.50       2
## 75   25 Female      570       61       81       76  3.00  3.25       2
## 76   25   Male      660       94       84       94  3.27  3.75       2
## 77   25   Male      680       94       92       97  3.17  3.50       2
## 88   26 Female      560       64       71       72  3.20  3.25       2
## 89   26   Male      560       87       41       72  3.00  3.00       2
## 90   26   Male      530       68       54       62  3.09  3.17       2
## 92   27   Male      720       99       95       99  3.10  3.25       2
## 93   27   Male      590       60       87       81  3.00  2.75       2
## 97   28   Male      620       81       90       89  3.20  3.00       2
## 98   28 Female      610       85       78       86  3.10  3.00       2
## 100  29   Male      660       94       87       94  3.00  3.00       2
## 102  29   Male      510       57       50       55  3.27  3.40       2
## 103  29 Female      640       90       84       92  3.20  3.00       2
## 104  29   Male      610       91       62       86  3.10  3.67       2
## 106  29   Male      580       79       67       78  3.00  3.25       2
## 107  30   Male      680       97       87       96  3.00  3.00       2
## 109  32 Female      610       64       89       86  3.25  0.00       2
## 110  35   Male      540       43       78       65  3.20  3.25       2
## 111  35   Male      630       66       95       90  3.08  3.25       2
## 112  36 Female      530       48       71       62  3.00  2.50       2
## 113  36   Male      650       87       89       93  3.00  3.20       2
## 114  43   Male      630       82       87       89  3.10  3.00       2
## 140  23   Male      720       95       98       99  2.80  2.50       3
## 141  24 Female      640       94       78       92  2.90  3.25       3
## 142  24   Male      710       96       97       99  2.80  2.75       3
## 143  24   Male      670       94       89       96  2.70  3.00       3
## 144  24 Female      710       97       97       99  2.80  3.00       3
## 146  24   Male      600       89       62       83  2.90  3.00       3
## 147  24 Female      640       96       71       91  2.70  2.50       3
## 150  25   Male      550       72       58       69  2.90  3.00       3
## 151  25   Male      710       99       91       98  2.90  3.25       3
## 159  26   Male      560       56       81       72  2.80  3.25       3
## 160  26   Male      540       52       71       65  2.70  2.75       3
## 162  26 Female      570       48       89       75  2.82  2.50       3
## 163  26   Male      610       82       81       86  2.90  2.75       3
## 164  27   Male      650       89       84       93  2.90  3.00       3
## 165  27 Female      550       66       63       69  2.90  3.00       3
## 167  27   Male      610       97       45       86  2.70  2.50       3
## 168  27 Female      630       82       89       89  2.70  3.25       3
## 169  27 Female      560       61       74       73  2.80  3.25       3
## 180  29   Male      590       92       58       81  2.80  2.75       3
## 182  32   Male      550       52       78       71  2.70  2.75       3
## 183  34   Male      610       79       81       86  2.80  3.00       3
## 184  34   Male      610       82       78       86  2.70  3.00       3
## 185  43   Male      480       49       41       45  2.90  3.25       3
## 213  25   Male      730       98       96       99  2.40  2.75       4
## 218  25   Male      700       99       87       98  2.00  2.00       4
## 219  26   Male      660       93       87       95  2.60  2.00       4
## 220  26   Male      450       28       46       34  2.10  2.00       4
## 222  26   Male      600       75       78       83  2.20  2.25       4
## 227  27 Female      560       59       74       73  2.40  2.50       4
## 229  27   Male      630       93       78       91  2.10  2.50       4
## 230  27   Male      580       84       58       78  2.70  2.75       4
## 232  27   Male      670       89       91       95  3.60  3.25       4
## 233  27   Male      580       74       70       78  3.40  3.25       4
## 234  28   Male      560       74       67       73  3.60  3.60       4
## 236  28   Male      710       94       98       99  3.40  3.75       4
## 237  28   Male      570       69       71        0  2.30  2.50       4
## 238  29   Male      530       35       81       62  3.30  2.75       4
## 241  29   Male      670       91       91       95  3.30  3.25       4
## 242  29   Male      630       99       50       89  2.90  3.25       4
## 243  29 Female      680       89       96       96  2.80  3.00       4
## 244  30   Male      650       88       92       93  3.45  3.83       4
## 250  31   Male      570       75       62       75  2.80  3.00       4
## 253  32   Male      510       79       22       54  2.30  2.25       4
## 254  35   Male      570       72       71       75  3.30  4.00       4
## 255  39 Female      700       89       98       98  3.30  3.25       4
##     work_yrs frstlang salary satis
## 1          2  English      0     7
## 2          2  English      0     6
## 3          2  English      0     6
## 4          1  English      0     7
## 6          2  English      0     6
## 7          2  English      0     5
## 8          2  English      0     6
## 22         3  English      0     6
## 23         1    Other      0     5
## 24         5  English      0     5
## 25         3  English      0     5
## 27        10  English      0     7
## 28         5  English      0     5
## 29         7  English      0     6
## 31         7  English      0     6
## 32         9  English      0     6
## 33        13  English      0     5
## 34        22  English      0     6
## 70         1  English      0     5
## 71         2  English      0     7
## 72         0    Other      0     5
## 73         2  English      0     6
## 74         1  English      0     5
## 75         3  English      0     4
## 76         2  English      0     5
## 77         2  English      0     6
## 88         3  English      0     6
## 89         3  English      0     6
## 90         4    Other      0     5
## 92         5  English      0     5
## 93         3  English      0     6
## 97         4  English      0     6
## 98         5  English      0     6
## 100        1  English      0     6
## 102        5  English      0     5
## 103        3  English      0     5
## 104        7  English      0     5
## 106        4  English      0     6
## 107        4  English      0     5
## 109       11  English      0     7
## 110        8  English      0     5
## 111       12  English      0     5
## 112        7  English      0     5
## 113       18  English      0     6
## 114       16  English      0     5
## 140        1  English      0     5
## 141        2    Other      0     4
## 142        2  English      0     7
## 143        2  English      0     7
## 144        2  English      0     7
## 146        1  English      0     6
## 147        2  English      0     6
## 150        3  English      0     6
## 151        1  English      0     6
## 159        4  English      0     6
## 160        2  English      0     6
## 162        3  English      0     5
## 163        3  English      0     6
## 164        2  English      0     6
## 165        3  English      0     4
## 167        4    Other      0     5
## 168        5  English      0     6
## 169        5  English      0     6
## 180        3    Other      0     5
## 182        7  English      0     6
## 183       11  English      0     6
## 184       12  English      0     5
## 185       22  English      0     5
## 213        2  English      0     6
## 218        1  English      0     7
## 219        2  English      0     5
## 220        4  English      0     6
## 222        2  English      0     6
## 227        2  English      0     5
## 229        4  English      0     5
## 230        1  English      0     5
## 232        5  English      0     6
## 233        3  English      0     6
## 234        5  English      0     5
## 236        6  English      0     6
## 237        5  English      0     5
## 238        6  English      0     7
## 241        3  English      0     5
## 242        1    Other      0     4
## 243        4  English      0     5
## 244        2  English      0     6
## 250        1  English      0     6
## 253        5    Other      0     5
## 254        8  English      0     6
## 255        5  English      0     5

DataFrame-4

Placed <- MBA_Data[which(MBA_Data$salary>999),]
dim(Placed)
## [1] 103  13

Two-way contingency Table of Sex & FirstLanguage

sex_Flang <- xtabs(~MBA_Data$sex+MBA_Data$frstlang)
addmargins(sex_Flang)
##             MBA_Data$frstlang
## MBA_Data$sex English Other Sum
##       Female      60     8  68
##       Male       182    24 206
##       Sum        242    32 274

One-way contingency Table of Satisfaction value

satisfaction <- xtabs(~MBA_Data$satis)
addmargins(satisfaction)
## MBA_Data$satis
##   1   2   3   4   5   6   7 998 Sum 
##   1   1   5  17  74  97  33  46 274
prop.table(satisfaction)*100
## MBA_Data$satis
##          1          2          3          4          5          6 
##  0.3649635  0.3649635  1.8248175  6.2043796 27.0072993 35.4014599 
##          7        998 
## 12.0437956 16.7883212

We can clearly see that morethan 74% of students have mentioned a satisfaction value of more than four. (i.e,>4).

Mean of Placed MBA Students as per Gender.

PlacedSalaryMean <- aggregate(Placed$salary,list(Gender=Placed$sex),mean)
PlacedSalaryMean
##   Gender         x
## 1 Female  98524.39
## 2   Male 104970.97

Placed Students as per Age.

table(Placed$age)
## 
## 22 23 24 25 26 27 28 29 30 31 32 33 34 39 40 
##  1  5 16 23 14 14  8  6  6  4  1  1  1  1  2

Mean of Placed MBA Students as per Age.

AgeSalaryMean <- aggregate(Placed$salary,list(Gender=Placed$age),mean)
AgeSalaryMean
##    Gender         x
## 1      22  85000.00
## 2      23  91651.20
## 3      24 101518.75
## 4      25  99086.96
## 5      26 101665.00
## 6      27 102214.29
## 7      28 103625.00
## 8      29 102083.33
## 9      30 109916.67
## 10     31 100500.00
## 11     32 107300.00
## 12     33 118000.00
## 13     34 105000.00
## 14     39 112000.00
## 15     40 183000.00

Drawing Box Plots / Bar Plots to visualize the distribution of each variable independently

Histograms

Using ‘lattice’ to have a clear idea of percent value of distribution based on “GMAT Score”, “Sex”,“Age”, “WorkExperience”

library(lattice)
histogram(Placed$gmat_tot,main="Histogram of Total GMAT Score", xlab = "GMAT Total",ylab = "Percent",col= "Yellow",las=1)

library(lattice)
histogram(Placed$sex, main="Histogram of Total GMAT Score", xlab = "GMAT Total",ylab = "Percent",col= "Yellow",las=1)

library(lattice)
histogram(Placed$age, main="Histogram of Total GMAT Score", xlab = "GMAT Total",ylab = "Percent",col= "Yellow",las=1)

library(lattice)
histogram(Placed$work_yrs,main="Histogram of Total GMAT Score", xlab = "GMAT Total",ylab = "Percent",col= "Yellow",las=1)

BoXplots

par(mfrow=c(1,2))
boxplot(Placed$salary~Placed$gmat_tot,col=c("red","blue","yellow","orange","green"),horizontal=TRUE,main="GMAT Score Based Salary Distribution",xlab="Salary of MBA Students",ylab="GMAT Score" )

boxplot(Placed$salary~Placed$work_yrs,horizontal=TRUE,col=c("red","blue","yellow","orange","green"),main="Work Exp. Based Salary Distribution",xlab="Salary of MBA Students",ylab="Work Exp.")

boxplot(Placed$salary~Placed$age,horizontal=TRUE,col=c("red","blue","yellow","orange","green"),main="Age wise Salary Distribution",xlab="Salary of MBA Students",ylab="Age")

par(mfrow=c(3,1))
boxplot(Placed$salary~Placed$sex,horizontal=TRUE,col=c("Yellow"),main="Gender Based Salary Distribution",xlab="Salary of MBA Students",ylab="Sex")

boxplot(Placed$salary~Placed$quarter,horizontal=TRUE,col=c("red","blue","yellow","orange"),las=1,main="Quarter Ranking Based Salary Distribution")

boxplot(Placed$salary~Placed$frstlang,horizontal=TRUE,las=1,col=c("Yellow"), main="First Language Based Salary Distribution")

Scatterplots

par(mfrow=c(1,3))
plot(x=Placed$gmat_tot,y=Placed$salary,pch=19,col=c("red","yellow"),xlab="GMAT Score",ylab = "Salary")
plot(x=Placed$work_yrs,y=Placed$salary,pch=19,col=c("red","yellow"),xlab="Work Experience",ylab = "Salary")
plot(x=Placed$age,y=Placed$salary,pch=19,col=c("red","yellow"),xlab="Age",ylab = "Salary")

ScatterPlotMatrix

library(car)
## 
## Attaching package: 'car'
## The following object is masked from 'package:psych':
## 
##     logit
scatterplotMatrix(~Placed$gmat_tot+Placed$work_yrs+Placed$sex+Placed$age+Placed$salary)

OBSERVATIONS: 1) Salary decreases with the increase in TOtal Gmat Score. 2) Salary Increases with the increase in Work Experience. 3) Salary Increases with the increase in Age. 4) Salary of Females is less than the Salary of Males.

Corrgram

library(corrgram)
corrgram(Placed,upper.panel = panel.pie,lower.panel = panel.shade,text.panel = panel.txt)

From the Corrgram, we can deduce that “Salary” is only positively correlated with the “Age”, “S_avg”,“Work_Yrs”