According to www.fueleconomy.gov, a random sample of seven 2016 Subaru Forester AWD2.5 L, 4 cyl, automatic cars gave a mean of 26.4miles per gallon (MPG). Assume MPG for this vehicle follow a normal distribution with a standard deviation of 3.23 MPG.
a) A rental company wishes to infer on the mean MPG for this vehicle. Construct a 90% confidence interval.
b) Interpret the confidence interval found in part (a).
c) Suppose that before constructing the confidence interval, the rental company’s boss decided that if the true mean MPG of the 2016 Subaru Forester was 32 MPG, he would add some of those vehicles to their fleet. Should he instruct the staff to simply increase the confidence level to simply ensure it includes that mean value?