A researcher wishes to estimate the number of days it takes an automobile dealer to sell a Proton X70. A sample of 90 cars had a mean time on the dealer’s lot for 7 days. Assume the population...

A researcher wishes to estimate the number of days it takes an automobile dealer to sell a
Proton X70. A sample of 90 cars had a mean time on the dealer’s lot for 7 days. Assume the
population standard deviation to be 1.5 days. Find the best point estimate of the population
mean and the 95% confidence interval of the population mean