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?

Null hypothesis: H0

And

Alternative hypothesis: Ha

Step-by-step explanation:

In this question,

Null hypothesis:

H0 : µ = 0.04

Alternative hypothesis:

Ha : µ < 0.04

The reasons for these are based on the fact below:

H0 will always be stated as an equality claim.

If θ denotes the parameter of interest, the null hypothesis will

have the form

H0 : θ = θ0

where θ0 is a specified number called the null value of the parameter.

Also, The alternative to the null hypothesis H0 : θ = θ0 will look like one of the following three assertions:

Ha : θ > θ0

Ha : θ < θ0

Ha : θ 6= θ0

the answer will be the last one

x = 3 ± √(5+y)