Question

To make a decision on whether or not to switch to a different shipping​ company, 18 random samples of 50 deliveries each were collected and the number of late deliveries out of the respective 50 deliveries was counted. The results are shown below.

Sample

Sample	Late deliveries
1	7
2	4
3	4
4	7
5	3
6	4
7	4
8	6
9	2
10	3
11	4
12	2
13	6
14	8
15	4
16	3
17	8
18	8

To make a decision on whether or not to switch to a different shipping​ company, 18 random samples of 50 deliveries each were collected and the number of late deliveries out of the respective 50 deliveries was counted. The results are shown below.

SAMPLE	LATE DELIVERIES
1	7
2	4
3	4
4	7
5	3
6	4
7	4
8	6
9	2
10	3
11	4
12	2
13	6
14	8
15	4
16	3
17	8
18	8

What is the centerline used in constructing a​ p-chart? Round to four decimal places.

A. 0.0967

B. 0.0657

C. 4.8333

D. 0.0348

Answer 1

A. 0.0967

Sample size	50
Number of samples	18
	Proportion defective
Upper Control Limit, UCL	0.2220
Center	0.0967
Lower Control Limit, LCL	0.0000

Control Chart for the Proportion Defective 0.25 0.2220 0.20 0.15 Sample Proportion Defective 0.10 0.0967 0.05 0.00 1 2 اليا 4 5 6 7 0.0000 8 10 11 12 13 14 15 16 17 18 Sample Number