Problem 16. Samples of size 5 provided the following 20 sample means for a production process that is believed to be in control.

95.72 95.24 95.18

95.4495.46 95.32

95.4095.44 95.08

95.50 95.8095.22

95.56 95.22 95.04

95.72 94.82 95.42

95.60 95.78

a. Based on these data, what is an estimate of the mean when the process is in control?

b. Assume that the process standard deviation is = .50. Develop the control chart for this production process. Assume that the mean of the process is the estimate developed in part (a).

c. Do any of the 20 sample means indicate that the process was out of control.

95.56 95.22 95.04

Problem 19

The following are quality control data for a manufacturing process at Kensport Chemical Company. The data show the temperature in degrees centigrade at five points in time during a manufacturing cycle. The company is interested in using control charts to monitor the temperature of its manufacturing process. Construct the chart and R chart. What conclusions can be made about the quality of the process?

Sample R Sample R

1 95.72 1.0

Sample x R

1 95.72 1.0

2 95.24 .9

3 95.18 .8

4 95.44 .4

5 95.46 .5

6 95.32 1.1

7 95.40 .9

8 95.44 .3

9 95.08 .2

10 95.50 .6

11 95.80 .6

12 95.22 .2

13 95.56 1.3

14 95.22 .5

15 95.04 .8

1695.721.1

17 94.82 .6

18 95.46 .5

19 95.60 .4

20 95.74 .6