A survey asked college freshman how far away from their hometown is from the college campus. A random sample of 36 students is taken with a mean distance of 100 miles and a standard deviation of 30 miles. Complete parts (a) and (b) below. (a) Find the 95% confidence interval for the population mean. Lower bound = Upper bound = (Round your answer to one decimal place.) (b) Suppose you want the estimate to be within 3 miles of the population mean. Determine the minimum sample size needed to construct a 95% confidence interval for the population mean under this condition. Minimum sample size = (Your answer must be a whole number.)