1) A quality engineer is constructing a control chart to determine whether three machines, all producing the same product, are in control with regard to a particular quality attribute. Accordingly, she inspected 100 units of output from each machine in random samples, with the following results.

Machine Total Defectives

#1 3

#2 2

#3 4

What is the estimate of the process proportion of defectives?

1. .01
2. .02
3. .03
4. .04
5. .05

2) Using the information in problem #1, what is the estimate of the standard deviation of the sampling distribution of sample proportions for this process?

A) .007

B) .010

C) .017

D) .020

E) .025

3) Using the information in problem #1, for upper and lower control limits of .052 and .018, which machine(s), if any, appear(s) to be out-of-control for process proportion of defectives?

1. #1
2. #2
3. #1, #3
4. None of the machines
5. All of the machines