Create a research question for which the appropriate test of the statistical hypothesis would require the use of a z-score.

The research question should include the independent and dependent variables you would study, an explanation of whether a one- or two-tail test is most appropriate, your testable null and alternative hypothesis, and an explanation of which alpha level you would select and a justification of your choice.

1. When a robot welder is in adjustment, its mean time to perform its task is 1.325 minutes. Past experience has found the standard deviation of the cycle time to be 0.0396 minutes. An incorrect mean operating time can disrupt the efficiency of other activities along the production line. For a recent sample of 80 jobs, the mean cycle time for the welder was 1.3229 minutes. Does the machine appear to be in need of adjustment?