What test do we use if population variances are known?

Answer: z-test: two sample for means

What is an alternative step to the critical value comparison?

Answer: compare the p-value to alpha

What do we do if the test statistic is in the non rejection region?

Answer: We fail to reject the null hypothesis

What do we do if the test statistic falls into a rejection region?

Answer: we reject the null hypothesis

What does the critical value do?

Answer: Divides the sampling distribution into a rejection region and a non rejection region

How do know if we reject or fail to reject?

Answer: We need to compare the test statistic to the critical value