Chapter 9.3, Problem 98E

(a)

To determine

To find: if the sample or the experiment is designed properly.

Explanation of Solution

A significance test tests the claim made. It investigates the claim by forming the null hypothesis and alternate hypothesis. It accepts or rejects the hypothesis on the basis of p- value. It cannot check whether the sample or the experiment is properly designed or not.

(b)

To determine

To find if the observed effect is due to chance.

Explanation of Solution

Yes, the significance test finds that the observed effect is due to chance . The significance test measures the observed difference between the group using the p- value. The observed effect is due to chance only if the observed effect has a value more than calculated value at the given significance level.

If the $p-value<\alpha$ , accept the null hypothesis.

If the $p-value\ge \alpha$ reject null hypothesis.

In the second case, observed effect has a value more than calculated value.

(c)

To determine

To explain: if the observed effect is important.

Explanation of Solution

A significance test tests the claim made. It cannot tell if the observed effect is important or not. It can only test the claim on the basis of p-value and cannot check if the observed effect is important.