Refer to Exercise. Suppose that in addition to recording the coffee sales, the manager also recorded the average temperature (measured in degrees Fahrenheit) during the game. These data together with the number of cups of coffee sold were recorded.

a. Compute the coefficient of determination.

b. Determine the coefficients of the least squares line.

c. What have you learned from the statistics calculated in parts (a) and (b) about the relationship between the number of cups of coffee sold and the temperature?

d. Discuss the information obtained here and in Exercise. Which is more useful to the manager?