Discuss the below:
Q: Ford Motor Company wishes to estimate the mean dollar amount of damage done to a 1995 Taurus as result of a 10 mph crash into the rear bumper of a parked car. 36 Tauruses are test crashed into parked cars and the dollar amount of damage done to each is recorded. The results are x-bar = $438 and s=$86.
a. Compute the 90% confidence interval for the mean amount of damage. Interpret this interval.
b. How many cars should be tested if Ford wants to be 90% confident of being within $10 of the population mean amount of damage? Assume the sample size will be larger than 30 (so you can use z distribution).