4. In a large city, the percent of total spending that households devote to housing isnormally distributed, with mean u and standard deviation o= 9%. I select asimple random sample of four young households and determine the percent oftheir total spending that is devoted to housing. The four percentages are
33% 39% 32% 36%
Based on these data, a 99% confidence interval forμis
(A)35%±5.78%.
(B)35%±8.82%
(C)35%±11.59%
(D)35%±23.18%