In: Statistics and Probability
A survey of MBA graduates of a business school obtained data on the first-year salary after graduation and years of work experience prior to obtaining their MBA. The data are given in excel.
1. Run the regression analysis (Include all options). Report the least squares regression line. Give the 95% confidence interval for the least squares estimate of the slope. Report the correlation coefficient. Interpret. Report the coefficient of determination. Interpret. and Use the ANOVA output and write out the hypothesis being tested, the test statistic, the critical value, p-value, and fully write out the conclusion.
Experience | Salary |
8 | 113.9 |
5 | 112.5 |
5 | 109 |
11 | 125.1 |
4 | 111.6 |
3 | 112.7 |
3 | 104.5 |
3 | 100.1 |
0 | 101.1 |
13 | 126.9 |
14 | 97.9 |
10 | 113.5 |
2 | 98.3 |
2 | 97.2 |
5 | 111.3 |
13 | 124.7 |
1 | 105.3 |
5 | 107 |
1 | 103.8 |
5 | 107.4 |
5 | 100.2 |
7 | 112.8 |
4 | 100.7 |
3 | 107.3 |
3 | 103.7 |
7 | 121.8 |
7 | 111.7 |
9 | 116.2 |
6 | 108.9 |
6 | 111.9 |
4 | 96.1 |
6 | 113.5 |
5 | 110.4 |
1 | 98.7 |
13 | 120.1 |
1 | 98.9 |
6 | 108.4 |
2 | 110.6 |
4 | 101.8 |
1 | 104.4 |
5 | 106.6 |
1 | 103.9 |
4 | 105 |
1 | 97.9 |
2 | 104.6 |
7 | 106.9 |
5 | 107.6 |
1 | 103.2 |
1 | 101.6 |
0 | 99.2 |
1 | 101.7 |
6 | 120.1 |
Following is the output of excel:
SUMMARY OUTPUT | ||||||
Regression Statistics | ||||||
Multiple R | 0.694650458 | |||||
R Square | 0.482539258 | |||||
Adjusted R Square | 0.472190044 | |||||
Standard Error | 5.555951324 | |||||
Observations | 52 | |||||
ANOVA | ||||||
df | SS | MS | F | Significance F | ||
Regression | 1 | 1439.269475 | 1439.26948 | 46.6256877 | 1.11404E-08 | |
Residual | 50 | 1543.429756 | 30.8685951 | |||
Total | 51 | 2982.699231 | ||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | |
Intercept | 100.6157023 | 1.291837902 | 77.8857023 | 7.3154E-54 | 98.02096955 | 103.210435 |
Experience, X | 1.490621382 | 0.218300495 | 6.8283005 | 1.114E-08 | 1.052151941 | 1.929090822 |
The least square regression line is
y' = 100.6157 + 1.4906*x
The 95% confidence interval for the least squares estimate of the slope is (1.0522, 1.9291).
Since slope is positive so correlation coefficient is also positive. The correlation coefficient is
r = 0.695
It shows a strong positive relationship between the variables.
The coefficient of determination is
It shows that 48.25% of variation in salary is explained by salary.
---------------------------
Hypotheses are:
The test statistics is
F = 46.63
The p-value is
p-value = 0.0000
Since p-value is less than 0.05 so we reject the null hypothesis. That is model is significant.