Question

The cooling system in a nuclear submarine requires the specifications that the average weld strength must meet or exceed 150 psi for proper coolant circulation. A random sample of 36 welds results in x ̅=157 psi and s=15 psi. A design engineer wants to test the specifications based on the sample information at 5% level of significance. Complete the hypothesis test by answering the following questions.

State the hypotheses.

Calculate the test statistic.

What is/are the critical value(s)?

What is your decision?

What is the conclusion/interpretation of this decision?

Calculate 95% CI for mean psi strength, and comment on your result.

Answer 1