Question

A researcher wants to conduct a study to determine whether exercising for 15 minutes helps to improve memory in patients with early-stage Alzheimer's disease compared with reading for 15 minutes. At a large medical clinic, 150 patients with early-stage Alzheimer's disease are available to participate in this study.

Answer 1

Part A

The proposed design is shown in the explanation below

Part B

We conclude after making our decision that :

Type II Error is more serious because in this error ,the clinic will not offer free service to patients, which will be very effective.

Explanation:

Part A:

We will have to divide 150 patients into 2 groups:

One group, of 75 patients, is control group without exercising.

The other group of 75 patients with exercising for 15 minutes.

Then we will test if the memory of the other group is more than that of the control group.

Part B

H0: There is no difference in mean improvement

HA: Alternative Hypothesis: There is difference in mean improvement'

Type I Error: Rejection of a true null hypothesis.

Assuming in reality there is no difference in mean improvement. But, due to hypothesis testing, we wrongly conclude that there is difference in mean improvement.

Then Type I Error is committed in this case. The result of this error is that only if the clinic will offer this exercise as a free service, which is not at all effective.

Type II Error: Retaining a false null hypothesis.

Assuming in reality there is difference in mean improvement. But due to hypothesis testing, we wrongly conclude that there is no difference in mean improvement.

Then Type II Error is committed in this case.

The result of this error is that the clinic will not offer this exercise therapy as a free service,which is very much needed.

Therefore;

Type II Error is more serious because in this error ,the clinic will not offer free service to patients, which will be very effective.