Question

For each example, identify the test or interval to be used. Then

state and check (as far as possible) the conditions.

1. A researcher takes 200 males over the age of 50 and randomly divides them into 2

groups. Group A takes one aspirin tablet per day, and group B takes a placebo tablet each

day. After one year, the researcher records whether or not each subject has had a

cardiovascular event (heart attacks, strokes, etc). She wishes to test the hypothesis that

aspirin reduces the likelihood of cardiovascular events in this population.

2.

From the same experiment as in question 1, another researcher wishes to test whether an

aspirin a day lowers blood pressure. He measures the blood pressure of the subjects in

group A before the study begins, and then again at the end of the study.

Answer 1

1. Here there are two different samples which are independent

The independent t-test, also called the two sample t -test, independent-samples t-test or student's t-test, is an inferential statistical test that determines whether there is a statistically significant difference or not.

So she needs to use t test for independent samples

2. Here it is paired data.

So here she needs to use paired t test for hypothesis