Question

3.) The standard deviation in the pressure required to open a certain valve is known to be sigma equals 0.8 psi. Due to changes in the manufacturing​ process, the​ quality-control manager feels that the pressure variability has increased . ​(a) Determine the null and alternative hypotheses. ​(b) Explain what it would mean to make a Type I error. ​(c) Explain what it would mean to make a Type II error.

Answer 1

a)

Null: Standard deviation equals 0.8

Alt: Standard deviation does not equal 0.8

b)

In statistical hypothesis testing, a type I error is the rejection of a true null hypothesis (also known as a "false positive" finding or conclusion), while a type II error is the failure to reject a false null hypothesis (also known as a "false negative" finding or conclusion).

Type 1 error would be declaring that Standard deviation does not equal 0.8 when it is 0.8

c)

type 2 error would be declaring that Standard deviation equals to 0.8 when it is not