a b The mean preparation fee H&R Block charged retail customers in 2012 was $273 (The Wall Street Journal). Use this price as the population mean and assume the population standard deviation of preparation fees is $100. (3-points) What is the probability that the mean price of a sample of 30 H&R Block real customers is within $16 of the population mean? (3-points) What is the probability that the mean price for a sample of 50 H&R Block retail customers is within $16 of the population mean? C (2-points) What is the probability that the mean price for a sample of 100 H&R Block customers is within $16 of the population mean? d (2 points) Which, if any, of the sample sizes in parts a, b, and c would you recommend to have at least of a 0.95 probability that the sample mean is within $16 of the population mean?