A sample of size 100 selected from one population has 60 successes, and a sample of size 150 selected from a second population has 95 successes. The test statistic for testing the equality of the population proportions is equal to:
A) -0.5319.
B) 0.7293.
C) -0.419.
D) 0.2702.

Question

Quizplus · Accepted Answer

The test statistic for testing the equality of the population proportions is:z = (p1 - p2) / sqrt(p(1-p)(1/n1 + 1/n2))where p1 and p2 are the sample proportions, n1 and n2 are the sample sizes, and p is the pooled proportion.In this case, p1 = 60/100 = 0.6, p2 = 95/150 = 0.6333, n1 = 100, n2 = 150, and p = (60 + 95) / (100 + 150) = 0.6167.Therefore, z = (0.6 - 0.6333) / sqrt(0.6167(1-0.6167)(1/100 + 1/150)) = -0.5319.

A Sample of Size 100 Selected from One Population Has