1. A local newspaper has 10 delivery boys who each deliver the morning newspaper to 50 customers every day. The owner decides to record the percentage of papers delivered on time for a 10-day period and construct a p chart to see whether the percentage is too erratic. ???
Day Percentage of Papers Delivered on Time ?
1 91?
2 89?
3 92?
4 90?
5 86?
6 96?
7 91?
8 98?
9 95?
10 93??
Referring to the table above set up a p chart for him.
2. A process that produces titanium forgings for automobile turbocharger wheels is to be controlled through use of a number of nonconformities chart. Initially, one sample is taken each day and checked for nonconformities for 20 days, and the results shown here are observed.
Day Nonconforming Units
1 3
2 2
3 4
4 2
5 5
6 2
7 1
8 2
9 0
10 5
11 2
12 4
13 1
14 3
15 6
16 0
17 1
18 2
19 3
20 2
Establish a control chart to monitor future production.
3. A textile company uses a u chart to monitor the number of nonconformities per roll of a fabric. 400 rolls of the fabric are inspected for defects per hour. The following table shows the data for 20 hours.
Hour Nonconforming units
1 12
2 11
3 9
4 15
5 7
6 6
7 5
8 10
9 8
10 8
11 14
12 5
13 9
14 13
15 7
16 5
17 8
18 11
19 7
20 12
Construct the chart for them.
nawaf89
scm_480_problems.docx
0
