Question

15) Which of the following statements are true?

I. If a population parameter is known, there is no reason to run a hypothesis test on that

population parameter.

II. The P -value can be negative or positive depending upon whether the sample statistic is less

than or greater than the claimed value of the population parameter in the null hypothesis.

III. The P -value is based on a specific test statistic so it must be chosen before an experiment is

conducted.

(A) I only (B) II only (C) III only (D) I and II (E) None are true

Answer 1

I. If a population parameter is known, there is no reason to run a hypothesis test on that population parameter.

We run a hypothesis testing to check a claim about the population parameter, using the sample statistics. If the population parameter is known, then we do not need to run any hyothesis test its validity.

II. The P -value can be negative or positive depending upon whether the sample statistic is less than or greater than the claimed value of the population parameter in the null hypothesis.

Pvalue is a probability, hence it lies between 0 and 1. It can only be postive number. Hence the statement is wrong.

III. The P -value is based on a specific test statistic so it must be chosen before an experiment is conducted.

The pvalue is an outcome of our hypothesis test, hence we cannot select it before an experiment is conducted. We need to select the level of signficance, which acts as a cutoff for the pvalue validation.

Correct anwer : (A) I only