Question

Random samples of sizes n1 = 400 and n2 = 315 were taken from two independent populations. In the first sample, 115 of the individuals met a certain criteria whereas in the second sample, 123 of the individuals met the same criteria. Run a 2PropZtest to test whether the proportions are different, and answer the following questions. What is the value of p−, the pooled sample proportion?Round your response to at least 3 decimal places. Number Calculate the z test statistic, for testing the null hypothesis that the population proportions are equal. Round your response to at least 2 decimal places. Number

Answer 1

The statistical software output for this problem is:

Hence,

Pooled sample proportion = (115 + 123)/(400 + 315) = 0.333

z test statistic = -2.90