
Chapter 17
722
Solution: The proportion of defective items for each sample can be computed by dividing
defective items by the number of items in the respective sample (Table 17.9).
The average of sample proportions can be computed as
p
pppp
k
=
=
+++⋅⋅⋅+
=
123
005006 003008
....
0.0476
qp=− =− =110 0476. 0.9524
TABLE 17.9
The proportion of defective pumps in a group of 100 water pumps
Sample n Defective Items Proportion (p
i
)
1 100 5 0.05
2 100 6 0.06
3 100 3 0.03
4 100 2 0.02
5 100 4 0.04
6 100 5 0.05
7 100 7 0.07
8 100 8 0.08
9 100 2 0.02
10 100 4 0.04
11 100 5 0.05
12 100 8 0.08
13 100 9 0.09
14 100 3 0.03
15 100 4 0.04
16 100 5 0.05
17 100 1 0.01
18 ...