To monitor the production of sheet metal screws by a particular machine in a large manufacturing company, a sample of 130 screws is examined each hour for two shifts of eight hours each. Each screw is inspected and designated as conforming or nonconforming according to specifications. Historically, the proportion of nonconforming screws has been 6%. Use the following results of one day’s sampling to construct a 3sigma p chart.
Nonconforming Screws
Sample Number Number Defective Sample Number Number Defective
1 7 9 14
2 10 10 13
3 6 11 12
4 7 12 5
5 16 13 12
6 15 14 10
7 19 15 18
8 11 16 17
Step 1 of 4 : Find the centerline for the control chart. Express the value as a percentage rounded to two decimal places, if necessary.
Step 2 of 4: Find the upper control limit for the control chart. Express the value as a percentage rounded to two decimal places, if necessary.
Step 3 of 4: Find the lower control limit for the control chart. Express the value as a percentage rounded to two decimal places, if necessary.
Steph 4 of 4: Which samples, if any, are out of control. Write the sample numbers in ascending order separated by commas. If there are no samples out of control, write None for your answer.
0/14 Correct
Question 1of 5,Step 1of 4
To monitor the production of sheet metal screws by a particular machine in a large manufacturing company,a sample of 130 screws is examined each hour for two shifts of eight hours each.Each screw is inspected and designated as conforming or nonconforming according to specifications. Historically, the proportion of nonconforming screws has been 6 % . Use the following results of one day's sampling to construct a 3 p chart.
Nonconforming Screws
Sample Number Number Defective
Sample Number
Number Defective
7 2
1 10
9
14
10
13
3
6
11
12
4
7
12
5
5
16
13
12
6
15
14
10
7
19
15
18
8
11
16
17
Copy Data
Step 1 of 4 : Find the centerline for the control chart. Express the value as a percentage rounded to two decimal places, if necessary.