Question

How is the rejection region defined and how is that related to the z-score and the p value? When do you reject or fail to reject the null hypothesis? Why do you think statisticians are asked to complete hypothesis testing? Can you think of examples in courts, in medicine, or in your area?

Answer 1

Acceptance or rejection of the null hypothesis depends on what level of significance you are using (e.g., P≤.05, P≤.01) and whether you are using a one-tailed or two-tailed test. If the Z score has that probability or less, reject the null hypothesis. If not, accept the null hypothesis.

We test the hypothesis to determine the probability that the differences found are due only to chance.

If you understand the concept, examples abound. I'll let you find them.

Answer 2

Random sample of n=25 scores is obtained from a population of a µ=70 .A treatment is administered to individuals in the sample and after treatment the sample mean M=78 with a standard deviation of s=20