A study is performed in San Antonio to determine whether the average weekly grocery bill per five-person family in the town is significantly different from the national average. A random sample of 50 five-person families in San Antonio showed a mean of $133.474 and a standard deviation of $11.193.

a. Assume that the national average weekly grocery bill for a five-person family is $131. Isthe sample evidence statistically significant at 5% significance level? What about 10%significance level?

b. For which values of the sample mean (i.e., average weekly grocery bill) would you decideto reject the null hypothesis at the 10% significance level?