70. Quality control. Production managers on an assembly line must monitor the output to be sure that the level of defective products remains small. They periodically inspect a random sample of the items produced. If they find a significant increase in the proportion of items that must be rejected, they will halt the assembly process until the problem can be identified and repaired.

a) Write null and alternative hypotheses for this problem.

b) What is the Type I and Type II error in this context?

c) Which type of error would the factory owner consider more serious?

d) Which type of error might customers consider more serious?