QUESTION 4

A. The Director of a private radio station (KXYZ) of a small city claimed that the average number of hours that its audience listen to its station is 4.3 hours per day. Its competitor refutes this claim. To proof that the director is wrong, the competitor conducted a survey on the listenership of the station. A random sample of 20 listeners was asked the number of hours they listen to the KXYZ station per day, and the findings are shown below: = 78.5,

Can we infer that the competitor is correct? Perform a test at 2.5% significance level. Assume that the population standard deviation is 0.65 hours.