According to the June 2004 Readers’ Digest article “Only in America,” the average amount that a 17-yearold spends on his or her high school prom is $638. Assume that the amounts spent are normally distributed with a standard deviation of $175.
a. Find the probability that the mean cost to attend a high school prom for 36 randomly selected 17-year-olds is between $550 and $700.
b. Find the probability that the mean cost to attend a high school prom for 36 randomly selected 17-yearolds is greater than $750.
c. Do you think the assumption of normality is reasonable? Explain.