"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, which is $131. A random sample of 50 five-person families in San Antonio showed a mean of $133.474 and a standard deviation of $11.193." Assume that the national average weekly grocery bill for a five-person family is $131. Is the sample evidence statistically significant? If so, at what significance levels can you reject the null hypothesis?