Assume that the relevant distribution is normal
Historical data indicate that household water use tends to be normally distributed with a mean of 360 gallons and a standard deviation of 40 gallons per day. To see if this is still the situation, a random sample of 200 households was chosen. The average daily water use in these households was then seen to equal 374 gallons per day.
(a) Are these data consistent with the historical distribution? Use the 5 percent level of significance.
(b) What is the p value?