Assuming that the tire mileage is normally distributed and the mean number of miles to failure is not known and a known ? = 3,700 miles. using your sample of 41 tires as your estimate of the mean (x bar); what is the upper and lower bound of a 95% confidence interval? (this was your question #2): suppose when you did this this calculation you found the error to be too large and would like to limit the error to 1000 miles. what should my sample size be?