Question

Let mu denote the true average number of minutes of a television commercial. Suppose the hypothesis H0: mu = 2.1 versus Ha: mu > 2.1 are tested. Assuming the commercial time is normally distributed, give the appropriate rejection region when there is a random sample of size 20 from the population and we would like to test at the level of significance 0.01. Let T be the appropriate test statistic. Group of answer choices

T > 2.539

T > 2.845

T > 2.528

T > 2.861

Answer 1

H0 : µ = 2.1   Vs Ha : µ > 2.1  

As alternative hypothesis have > sign. It is right tail test.

Decision Rule for right tail test:

1) If sample test statistic < critical value , fail to reject H0

2) If sample test statistics ≥ critical value, Reject H0.

So, region of rejection will be greater than critical value.

We have t statistic, with n =20 , degree of freedom = n-1 = 20-1 =19

Level of significance α = 0.01, and for one tail test.

Using t distribution table

t 0.01 , 19 = 2. 539

Appropriate region of rejection will be T > 2.539  

First option is correct answer.