試題詳解

17. A study was commissioned to compare the housing costs of two growing cities. The goal of the study was to estimate the difference in the average housing costs (as measured in price per square foot) of the two cities. Two pilot samples were taken and yielded the following information: Use this information to determine how large the sample sizes must be in order to estimate the true difference in the average housing costs of the two cities to within $1.25. Assume that equal sample sizes are desired and a 95% reliability level is essential.
(A)nl =n2 =76
(B) n1 =n2=84
(C)n1 =n2=119
(D)n1 =n2= 25