Other Variable Control Charts
Instructions: You must show your work including formula used, data tables (when necessary) charts, drawings, and calculations, not just the answers only. Without showing work but answers only will reduce value to 20% of its full value. If there is a problem to insert Math Editor in MS Word answer document, you can write on white paper, scan and insert as pictures.
1. A local doctor's office tracks the number of insurance claim rejections on a monthly basis. From the following information, create a chart for individuals with a moving-range chart. Interpret the chart.
|
Month
|
# of rejected claims
|
|
Nov.
|
42
|
|
Dec.
|
31
|
|
Jan.
|
58
|
|
Feb.
|
46
|
|
Mar.
|
58
|
|
Apr.
|
48
|
|
May
|
42
|
|
June
|
65
|
|
July
|
78
|
|
Aug
|
74
|
|
Sept.
|
58
|
|
Oct.
|
59
|
|
Nov.
|
45
|
|
Dec.
|
46
|
2. Eighteen successive heats of steel alloy are tested for Rockwell hardness. The resulting data are shown below. Setup control limits for the moving average and moving range charts for a sample size of n=4.
|
Heat
|
Hardness
|
Heat
|
Hardness
|
|
1
|
0.806
|
10
|
0.809
|
|
2
|
0.814
|
11
|
0.808
|
|
3
|
0.810
|
12
|
0.810
|
|
4
|
0.820
|
13
|
0.812
|
|
5
|
0.819
|
14
|
0.810
|
|
6
|
0.815
|
15
|
0.809
|
|
7
|
0.817
|
16
|
0.807
|
|
8
|
0.810
|
17
|
0.807
|
|
9
|
0.811
|
18
|
0.800
|