The National Highway Transportation Safety Administration’s National Center for Statistics and Analysis released its Vehicle Survivability Travel Mileage Schedules in January 2006. One item investigated was the relationship between the annual vehicle miles traveled (VMT) as a function of vehicle age for passenger cars up to 25 years old. The VMT data were collected by asking consumers to estimate the number of miles driven in a given year. The data were collected over a 14-month period. The file titled Miles contains this data.
a. Produce a regression equation modeling the relationship between VMT and the age of the vehicle. Estimate how many more annual vehicle miles would be traveled for a vehicle that is 10 years older than another vehicle.
b. Provide a 90% confidence interval estimate for the average annual vehicle miles traveled when the age of the vehicle is 15 years.
c. Determine if it is plausible for a vehicle that is 10 years old to travel 12,000 miles in a year. Support your answer with statistical reasoning.