According to the National Association of Theater Owners, the average price for a movie in the United States in 2017 was $8.97. Assume the population standard deviation is $0.50 and that a sample of 30 theaters was randomly selected. b. What is the probability that the sample mean will be less than $8.75 ? c. What is the probability that the sample mean will be less than $9.10 ? d. What is the probability that the sample mean will be more than $9.20