Question 3 (Ensure all work is shown) Not yet A survey conducted by a research team was set to investigate how years of education, tenure in answered current employment, and age, are related to annual income. A sample of 20 employees is Marked out of selected and the Excel Regression output is provided: 10.00 SUMMARY OUTPUT Flag Regression Statistics question Multiple R 0.949819857 R Square 0.90215776 Adjusted R Square 0.88381234 Standard Error 17275.00469 Observations 20 ANOVA df SS MS F Regression 3 7777 146754416.7 2777 Residual 16 47748125 Total 19 48801 1375 Coefficients Standard Error t Sto Intercept -74215.79876 21589.39824 3.437603862 Education (No. of years) 4364.741946 1542.536912 2.82958671 Length of tenure (No. of years) 6571.9131 1154.555085 5.692160718 Age (No. of years) 916.4669052 728.6505348 1.257759188 a) Write the population regression line. b) Test the validity of the model at 97.5%. c) Is there enough evidence to infer that if Length of tenure decreases, annual income also decreases? Test at the 99% confidence level. d) Estimate the Annual Income for a person with 15 years of education and who is 30 years of age. The length of tenure for the person is unavailable