Test statistic and critical value

Question

You wish to test the following claim (HaHa) at a significance level of α=0.02

      Ho:p1=p2

      Ha:p1>p2

You obtain 315 successes in a sample of size n1=694 from the first population. You obtain 235 successes in a sample of size n2=563 from the second population.

What is the critical value for this test? (Round to three decimal places.) 

Critical value = 

What is the test statistic for this sample? (Round to three decimal places.) 

Test statistic = 

Answer 1

critical value is right tail z-score for alpha = 0.02, which is z-score for cumulative 0.98 probability = 2.054

sample proportion 1 phat1 = 315/694 = 0.454

sample proportion 2 phat 2 = 235/563 = 0.471

sample size n1 = 694

sample size n2 = 563

pooled proportion p = (315 + 235) / (694 + 563) = 0.438

test statistic z = (0.454-0.471)/sqrt(0.438 * 0.562*(1/694 + 1/563)). = -0.604