Although there is a big difference in costs between two electric vehicles,model 1andmodel 2,is there a difference in the range of miles for these vehicles between charges? Suppose that the results of driving tests are as follows.

Car Mean StandardDeviation SampleSize

model 1 231.8 13.4 40

model 2 235.7 17.5 40

(a) Calculate a point estimate for the difference in the average ranges (in miles) between charges for amodel 1car and amodel 2car. (Use_{model 1model 2}.)

______mi

(b) What is the 95% margin of error (in miles) for the point estimate you found? (Round your answer to three decimal places.)

_______mi

(c) Find a 99% confidence interval estimate for the difference in the average ranges (in miles) between charges for these electric models. (Use_{model 1model 2}.Round your answers to two decimal places.)

_____mi to______mi