In: Statistics and Probability
Data has been gathered to explain executive salaries from a variety of factors.
Perform a Multiple Regression to predict SALARY from EXPerience, EDUCation, GENDER, NUMberSupported and ASSETS.
a. What is the regression equation? Write an interpretation of the regression equation
b. Calculate the coefficient of determination. How would you interpret this?
c. State the hypotheses to test for the significance of the independent factors. Using t-tests, at alpha= 0.05 determine which factors are significantly related to Executive SALARY
SALARY | EXP | EDUC | GENDER | NUMSUP | ASSETS |
93300 | 12 | 15 | 1 | 240 | 170 |
130000 | 25 | 14 | 1 | 510 | 160 |
88200 | 20 | 14 | 0 | 370 | 170 |
74400 | 3 | 19 | 1 | 170 | 170 |
115300 | 19 | 12 | 1 | 520 | 150 |
70400 | 14 | 13 | 0 | 420 | 160 |
114200 | 18 | 18 | 1 | 290 | 170 |
72600 | 2 | 17 | 1 | 200 | 180 |
108600 | 14 | 13 | 1 | 560 | 180 |
68600 | 4 | 16 | 1 | 230 | 160 |
102000 | 8 | 18 | 1 | 540 | 150 |
101400 | 19 | 15 | 1 | 90 | 180 |
149400 | 23 | 16 | 1 | 560 | 180 |
57100 | 5 | 15 | 0 | 470 | 150 |
87400 | 3 | 16 | 1 | 340 | 190 |
131000 | 22 | 17 | 1 | 70 | 200 |
90300 | 24 | 14 | 0 | 160 | 180 |
115600 | 22 | 16 | 1 | 160 | 190 |
102800 | 13 | 18 | 1 | 110 | 180 |
141900 | 21 | 16 | 1 | 410 | 180 |
90900 | 10 | 13 | 1 | 370 | 190 |
73400 | 11 | 12 | 1 | 180 | 170 |
101000 | 12 | 19 | 1 | 60 | 200 |
85400 | 10 | 19 | 1 | 60 | 180 |
138300 | 26 | 17 | 1 | 110 | 200 |
82300 | 7 | 15 | 1 | 280 | 190 |
85500 | 7 | 19 | 1 | 110 | 180 |
75300 | 10 | 19 | 0 | 300 | 170 |
87500 | 23 | 14 | 0 | 220 | 170 |
127100 | 12 | 15 | 1 | 570 | 200 |
80100 | 6 | 16 | 1 | 240 | 180 |
90900 | 15 | 16 | 0 | 300 | 150 |
109600 | 15 | 18 | 1 | 260 | 170 |
70700 | 8 | 13 | 1 | 150 | 160 |
104400 | 18 | 19 | 0 | 350 | 160 |
71200 | 2 | 13 | 1 | 370 | 190 |
85400 | 13 | 14 | 1 | 150 | 160 |
89300 | 12 | 17 | 0 | 480 | 190 |
124800 | 21 | 15 | 1 | 310 | 180 |
42800 | 3 | 12 | 0 | 340 | 150 |
125000 | 20 | 16 | 1 | 520 | 160 |
122200 | 20 | 19 | 1 | 200 | 170 |
107100 | 20 | 17 | 0 | 490 | 160 |
61000 | 1 | 15 | 0 | 570 | 180 |
59800 | 2 | 17 | 1 | 70 | 160 |
95700 | 9 | 17 | 1 | 300 | 160 |
85600 | 11 | 17 | 0 | 190 | 160 |
88900 | 21 | 13 | 0 | 500 | 160 |
143000 | 20 | 20 | 1 | 390 | 170 |
109200 | 17 | 16 | 0 | 520 | 180 |
156700 | 24 | 12 | 1 | 530 | 200 |
65100 | 2 | 17 | 0 | 590 | 190 |
105900 | 9 | 13 | 1 | 560 | 170 |
74300 | 2 | 18 | 0 | 600 | 190 |
79300 | 13 | 12 | 0 | 390 | 170 |
106600 | 14 | 18 | 1 | 110 | 170 |
106400 | 18 | 13 | 1 | 190 | 190 |
77400 | 10 | 14 | 1 | 110 | 160 |
129400 | 21 | 13 | 1 | 430 | 190 |
82600 | 11 | 14 | 0 | 440 | 150 |
126100 | 26 | 15 | 1 | 210 | 190 |
121900 | 22 | 18 | 1 | 320 | 160 |
96200 | 3 | 16 | 1 | 560 | 180 |
128900 | 17 | 18 | 1 | 450 | 190 |
72200 | 2 | 16 | 1 | 410 | 180 |
58800 | 4 | 18 | 0 | 70 | 150 |
79300 | 8 | 17 | 1 | 90 | 190 |
96100 | 13 | 15 | 1 | 290 | 160 |
94900 | 3 | 18 | 1 | 530 | 180 |
89000 | 13 | 16 | 0 | 420 | 170 |
108800 | 25 | 19 | 0 | 150 | 200 |
95300 | 11 | 15 | 1 | 500 | 190 |
71200 | 2 | 17 | 0 | 430 | 190 |
173400 | 26 | 17 | 1 | 570 | 190 |
107000 | 20 | 20 | 1 | 90 | 150 |
100000 | 19 | 12 | 1 | 340 | 160 |
100700 | 12 | 13 | 1 | 440 | 170 |
152800 | 22 | 18 | 1 | 500 | 160 |
95300 | 13 | 13 | 0 | 570 | 180 |
77300 | 2 | 15 | 1 | 560 | 190 |
84600 | 15 | 14 | 1 | 160 | 170 |
92600 | 12 | 13 | 1 | 390 | 190 |
85900 | 13 | 19 | 0 | 370 | 200 |
79400 | 5 | 17 | 1 | 330 | 160 |
80100 | 8 | 17 | 0 | 560 | 170 |
114100 | 21 | 20 | 0 | 590 | 180 |
78500 | 5 | 16 | 1 | 290 | 200 |
87300 | 9 | 18 | 0 | 440 | 180 |
102900 | 19 | 15 | 0 | 480 | 190 |
116300 | 23 | 19 | 1 | 130 | 150 |
51500 | 3 | 12 | 0 | 440 | 190 |
106500 | 13 | 19 | 1 | 310 | 150 |
109000 | 22 | 17 | 0 | 370 | 200 |
66600 | 9 | 12 | 0 | 180 | 160 |
111100 | 7 | 19 | 1 | 520 | 200 |
83100 | 10 | 18 | 0 | 90 | 180 |
159500 | 25 | 18 | 1 | 590 | 160 |
122500 | 10 | 19 | 1 | 480 | 200 |
67300 | 3 | 19 | 1 | 80 | 160 |
97900 | 16 | 17 | 0 | 380 | 160 |
Here we will use the multiple regression analysis of EXCEL.
THe excel regression output is given below
SUMMARY OUTPUT | ||||||||
Regression Statistics | ||||||||
Multiple R | 0.958728 | |||||||
R Square | 0.919159 | |||||||
Adjusted R Square | 0.914859 | |||||||
Standard Error | 7357.702 | |||||||
Observations | 100 | |||||||
ANOVA | ||||||||
df | SS | MS | F | Significance F | ||||
Regression | 5 | 5.79E+10 | 1.16E+10 | 213.7551 | 1.02E-49 | |||
Residual | 94 | 5.09E+09 | 54135775 | |||||
Total | 99 | 6.29E+10 | ||||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 95.0% | Upper 95.0% | |
Intercept | -42495.3 | 9898.371 | -4.29316 | 4.28E-05 | -62148.8 | -22841.9 | -62148.8 | -22841.9 |
EXP | 2635.586 | 100.8157 | 26.14262 | 6.57E-45 | 2435.414 | 2835.758 | 2435.414 | 2835.758 |
EDUC | 2666.489 | 326.8269 | 8.158719 | 1.48E-12 | 2017.566 | 3315.411 | 2017.566 | 3315.411 |
GENDER | 21981.03 | 1601.493 | 13.72534 | 3.53E-24 | 18801.23 | 25160.83 | 18801.23 | 25160.83 |
NUMSUP | 55.1606 | 4.642538 | 11.88156 | 2.01E-20 | 45.94273 | 64.37847 | 45.94273 | 64.37847 |
ASSETS | 168.8869 | 48.69802 | 3.468045 | 0.000793 | 72.19586 | 265.578 | 72.19586 | 265.578 |
(a)
Hre the regression equationis
Salary = -42495.3 + 2635.486 * Exp + 2666.489 * EDUC + 21981.03 * GENDER + 55.1606 * NUMSUP + 168.8869 * ASSETS
(b) Here the coeffficient of determination is 0.91915
so here we can interpret it as there is 91.915% variability could be explained by the independt variables.
(c) Here at alpha = 0.05,we will checkthe p - value of each independent variable and as we see that p - value for all the independent variables are less than 0.05 so each inddepepndent variable is significant here.