Question

Could really use some help solving a similar problem. Please breakdown your work and hopefully that'll help clarify it for me. Thanks for the help!

A company produces a popular type of cookies. The package indicates it contains 25.0 ounces of cookies. To ensure that the firm makes good in its marketing promo claim regarding box weight content, the inspection department makes hourly check on the production process. As part of the hourly check, four boxes are selected and their contents weighed. The results for 25 samples are reported below.

Sample Number	Weight-1	Weight-2	Weight-3	Weight-4
1	25.1	24.4	25.6	23.2
2	23.2	23.9	25.1	24.8
3	25.6	24.5	25.7	25.1
4	22.5	23.8	24.1	25
5	23.2	24.2	22.3	25.7
6	22.6	24.1	20	24
7	23	26	24.9	25.3
8	24.5	25.1	23.9	24.7
9	24.1	25	23.5	24.9
10	25.8	25.7	24.3	26
11	24.5	23	23.7	24
12	25.1	24.4	25.6	23.2
13	23.2	24.2	23	25.7
14	23.1	23.3	24.4	24.7
15	24.6	25.1	24	25.3
16	24.4	24.4	22.8	23.4
17	25.1	24.1	23.9	26.2
18	24.5	24.5	26	26.2
19	25.3	24.5	24.3	25.5
20	24.6	25.3	25.5	24.3
21	24.9	24.4	25.4	24.8
22	23.2	24.2	22.3	25.7
23	24.8	24.3	25	25.2
24	23.2	24.2	23	25.7
25	24.8	24.3	25	25.2

1. Develop the appropriate control charts to evaluate and monitor the boxing process
2. What do the control charts tell you about the process during the 25-hour inspection period (i.e. Do a thorough interpretation and analysis of the charts.)?

Answer 1

a) X-bar and R Control charts are drawn as follows:

b) X-bar chart indicate that the mean of Sample #6 is lower than the UCL. Therefore, the process is out of control.