The data from Exercise 4.69 for average high and low temperatures in January for a random sample of 50 cities are on the WeissStats CD.
a. Decide whether finding a regression line for the data is reasonable. If so, then also do parts (b)–(d).
b. Obtain the coefficient of determination.
c. Determine the percentage of variation in the observed values of the response variable explained by the regression, and interpret your answer.
d. State how useful the regression equation appears to be for making predictions.