Families of size 4 spent a population mean of $360 on a visit to an amusement park, standard deviation of $50 in October 2000. Operators want to know whether families will spend more in 2001. In an April exit poll, 64 randomly selected families of size 4 were interviewed with the average amount spent by families in the sample was $375. Assuming the standard deviation per family is $50, compute a 95% one sided confidence interval in the mean spending habits of these families. Is this sufficient evidece at 5% level of significance to indicate families will spend more in 2001?

Conduct the hypothesis test formally. If the true population mean of spending habits is $375, what is the power of this test.