72. Quality control, part 2. Consider again the task of the quality control inspectors in Exercise 70.

a) In this context, what is meant by the power of the test the inspectors conduct?

b) They are currently testing 5 items each hour.

Someone has proposed they test 10 items each hour instead.

What are the advantages and disadvantages of such a change?

c) Their test currently uses a 5% level of significance.

What are the advantages and disadvantages of changing to a significance level of 1%?

d) Suppose that as a day passes one of the machines on the assembly line produces more and more items that are defective. How will this affect the power of the test?