Discussion:
Q: A national car insurance company stated that in 1987, the average yearly car insurance cost for a family in the U.S. was $931. In the same year, a random sample of 39 families in california resulted in a mean cost of X = $975 with a standard deviation of = 30.50. Does this suggest that the average insurance cost for a family in california in 1987 exceeded the national average? Perform the hypothesis test at a significance level of 5%