A power company located in southern Alabama wants to predict the peak power load (i.e., the maximum amount of power that must be generated each day to meet demand) as a function of the daily high temperature (X). A random sample of 25 summer days is chosen, and the peak power load and the high temperature are recorded each day. The file P14_32.xlsx contains these observations.

a. Create a scatterplot for these data. Comment on the observed relationship between Y and X. 

b. Estimate an appropriate regression equation to predict the peak power load for this power |company. Interpret the estimated regression coefficients.

c. Analyze the estimated equation’s residuals. Do they suggest that the regression equation is adequate? If not, return to part b and revise your equation. Continue to revise the equation until the results are satisfactory.

d. Use your final equation to predict the peak power load on a summer day with a high temperature of 100 degrees.