The file P10_11.xlsx contains annual observations (in column B) of the American minimum wage. The basic question here is whether the minimum wage has been growing at roughly a constant rate over this period.
a. Create a time series graph for these data. Comment on the observed behavior of the minimum wage over time.
b. Estimate a linear regression equation of the minimum wage versus time (the Year variable). What does the estimated slope indicate?
c. Analyze the residuals from the equation in part b. Are they essentially random? If not, return to part b and revise your equation appropriately. Then interpret the revised equation.