The distribution of a population of mechanical aptitude test is normal, with a mean of 46 and a standard deviation of 4. To test the impact of a job training program, a sample of 26 scores was obtained from employees who took the training program. The sample yielded a mean score of 53. Test the hypothesis that the training program has a significant effect on mechanical aptitude score.
What is the standard error of the mean for this sample?
What is the z-score for this sample?
What z-score must be obtained from the sample in order to reject the null hypothesis at an alpha level of .05?
State the null hypothesis and the alternative hypothesis for a test based on expected values of the mean for those who did not receive treatment.