Question

To determine whether the pipe welds in a nuclear power plant meet specifications, a random sample of welds is selected, and tests are conducted on each weld in the sample. Weld strength is measured as the force required to break the weld. Suppose the specifications state that mean strength of welds should exceed 100 lb/in2; the inspection team decides to test H0: μ = 100 versus Ha: μ > 100. Explain why it might be preferable to use this Ha rather than μ < 100

Answer 1

H0: mu = 100

Ha: mu > 100

It is preferable to use this Ha than mu < 100 because it meets the specifications.

Explanation:

It is preferable to use mu > 100 as the alternate hypothesis than mu < 100 because the specifications state that mean strength of welds should exceed 100 lb/in^2.

Exceed is expressed using the inequality, greater than.

Therefore, the alternate hypothesis should be expressed using greater than.