Question

Suppose you want to test the claim that the mean is less than or equal to 25.6. Given a sample size of n = 40 with sample standard deviation of 2, and a level of significance of alpha = 0.05, when would you reject the null hypothesis?

Select one:

a. Reject null if the test statistic is greater than 1.96.

b. Reject null if the test statistic is greater than 2.021.

c. Reject null if the test statistic is greater than 1.645.

d. Reject null if the test statistic is greater than 1.685.

Answer 1

Solution :

This is the right tailed test .

The null and alternative hypothesis is

H₀ :  $\mu$$\leq$ 25.6

H_a : $\mu$ > 25.6

s = 40

n = 40

df = 39

$\alpha$ = 0.02

.t_0.05,39 = 1.685

d) Reject null if the test statistic is greater than 1.685.