Question

Before agreeing to purchase a large order of polyethylene sheaths for a particular type of high-pressure oil-filled submarine power cable, a company wants to see conclusive evidence that the true standard deviation of sheath thickness is less than 0.04 mm. What hypotheses should be tested, and why? The appropriate hypotheses are H0: σ

Answer 1

H0: σ=0.04mm

Ha: σ<0.04mm

Explanation:

The hypotheses that the company should test are:

H0: σ=0.04mm

Ha: σ<0.04mm

The null hypothesis indicates that a population parameter is equal to a hypothetical value. And the alternative hypothesis is what you expect to prove, in this case, the company wants to know if there is statistical evidence to prove that the standard deviation of the sheath thickness is less than 0.04 mm.