Quiz 4 Question 9: Hypothesis test for mean using T-Test

Last year the life of a battery produced by the manufacturer was 25 months. This new a new machine was installed and a sample of 25 batteries produced by the new machine yielded a sample average of 23.85 months and a sample standard deviation of 2.5. If we test H0: mu = 25 vs. Ha: mu does not equal 25, the data would lead us to which of the following conclusions:

a. Rejection of the null hypothesis at both the 0.05 and 0.01 level of significance.
b. Acceptance of the null hypothesis at both the 0.05 and 0.01 level of significance
c. Acceptance of the null hypothesis at 0.05 level of significance but rejection at 0.01 level of significance
d. Rejection of the null hypothesis at the 0.05 level of significance but acceptance at 0.01 level of significance.