Repeat given Exercise, but with average retail units sold per dealer as the independent variable and with the 95% interval estimates assuming a dealer group for which the average number of retail units sold per dealer is 1000.
Exercise
Information describing 98 of the top automobile dealership groups in the United States is provided in computer database file DEALERS. For calendar year 1999, the data include the number of dealers, the average number of retail units sold per dealer, and the total revenue for the dealership group. Determine the regression equation estimating total revenue as a function of the number of dealers.
For a dealership group consisting of 100 dealers, determine and interpret the 95% confidence and prediction intervals associated with total revenue.