|
5%
risk of over-reliance (95% confidence that the sample will detect errors) |
| Population |
|
|
|
|
|
|
|
|
|
|
|
| expected deviation |
Tolerable Deviation Rate |
| rate |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
| - |
149 |
99 |
74 |
59 |
49 |
42 |
36 |
32 |
29 |
19 |
14 |
| 0.25 |
236 |
157 |
117 |
93 |
78 |
66 |
58 |
51 |
46 |
30 |
22 |
| 0.50 |
|
157 |
117 |
93 |
78 |
66 |
58 |
51 |
46 |
30 |
22 |
| 0.75 |
|
208 |
117 |
93 |
78 |
66 |
58 |
51 |
46 |
30 |
22 |
| 1.00 |
|
|
156 |
93 |
78 |
66 |
58 |
51 |
46 |
30 |
22 |
| 1.25 |
|
|
156 |
124 |
78 |
66 |
58 |
51 |
46 |
30 |
22 |
| 1.50 |
|
|
192 |
124 |
103 |
66 |
58 |
51 |
46 |
30 |
22 |
| 1.75 |
|
|
227 |
153 |
103 |
88 |
77 |
51 |
46 |
30 |
22 |
| 2.00 |
|
|
|
181 |
127 |
88 |
77 |
68 |
46 |
30 |
22 |
| 2.25 |
|
|
|
208 |
127 |
88 |
77 |
68 |
61 |
30 |
22 |
| 2.50 |
|
|
|
|
150 |
109 |
77 |
68 |
61 |
30 |
22 |
| 2.75 |
|
|
|
|
173 |
109 |
95 |
68 |
61 |
30 |
22 |
| 3.00 |
|
|
|
|
195 |
129 |
95 |
84 |
61 |
30 |
22 |
| 3.25 |
|
|
|
|
|
148 |
112 |
84 |
61 |
30 |
22 |
| 3.50 |
|
|
|
|
|
167 |
112 |
84 |
76 |
40 |
22 |
| 3.75 |
|
|
|
|
|
185 |
129 |
100 |
76 |
40 |
22 |
| 4.00 |
|
|
|
|
|
|
146 |
100 |
89 |
40 |
22 |
| 5.00 |
|
|
|
|
|
|
|
158 |
116 |
40 |
30 |
| 6.00 |
|
|
|
|
|
|
|
|
179 |
50 |
30 |
| 7.00 |
|
|
|
|
|
|
|
|
|
68 |
37 |
|
|
Values indicate the sample size |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1) |
"I can be 95% sure that there is no more
than a 5% population deviation rate if my sample of 59 yields no
errors." |
| 2) |
"If I can live with a 5% population
deviation rate and honestly believe the population is error-free, I should
select 59 |
|
items for sampling. This sample is subject to a 5% risk that
the test does not detect an error ." |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
5% risk of over-reliance (95%
confidence that the sample will detect errors) |
|
|
|
|
|
|
|
|
|
|
|
|
| Sample |
Actual number (or %) of errors
encountered |
| Size |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
| 25 |
11.3 |
17.6 |
|
|
|
|
|
|
|
|
|
| 30 |
9.5 |
14.9 |
19.5 |
|
|
|
|
|
|
|
|
| 35 |
8.2 |
12.8 |
16.9 |
|
|
|
|
|
|
|
|
| 40 |
7.2 |
11.3 |
14.9 |
18.3 |
|
|
|
|
|
|
|
| 45 |
6.4 |
10.1 |
13.3 |
16.3 |
19.2 |
|
|
|
|
|
|
| 50 |
5.8 |
9.1 |
12.1 |
14.8 |
17.4 |
19.9 |
|
|
|
|
|
| 55 |
5.3 |
8.3 |
11.0 |
13.5 |
15.9 |
18.1 |
|
|
|
|
|
| 60 |
4.9 |
7.7 |
10.1 |
12.4 |
14.6 |
16.7 |
18.8 |
|
|
|
|
| 65 |
4.5 |
7.1 |
9.4 |
11.5 |
13.5 |
15.5 |
17.4 |
19.3 |
|
|
|
| 70 |
4.2 |
6.6 |
8.7 |
10.7 |
12.6 |
14.4 |
16.2 |
18.0 |
19.7 |
|
|
| 75 |
3.9 |
6.2 |
8.2 |
10.0 |
11.8 |
13.5 |
15.2 |
16.9 |
18.4 |
20.0 |
|
| 80 |
3.7 |
5.8 |
7.7 |
9.4 |
11.1 |
12.7 |
14.3 |
15.8 |
17.3 |
18.8 |
|
| 90 |
3.3 |
5.2 |
6.8 |
8.4 |
9.9 |
11.3 |
12.7 |
14.1 |
15.5 |
16.8 |
18.1 |
| 100 |
3.0 |
4.7 |
6.2 |
7.6 |
8.9 |
10.2 |
11.5 |
12.7 |
14.0 |
15.2 |
16.4 |
| 125 |
2.4 |
3.7 |
4.9 |
6.1 |
7.2 |
8.2 |
9.3 |
10.3 |
11.3 |
12.2 |
13.2 |
| 150 |
2.0 |
3.1 |
4.1 |
5.1 |
6.0 |
6.9 |
7.7 |
8.6 |
9.4 |
10.2 |
11.0 |
| 200 |
1.5 |
2.3 |
3.1 |
3.8 |
4.5 |
5.2 |
5.8 |
6.5 |
7.1 |
7.7 |
8.3 |
|
|
Table indicates the expected population
deviation rate |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1) |
"If my sample of 60 yields 0 errors, I
can be 95% sure that the population deviation rate is no more than 4.9%" |
| 2) |
"If my sample of 100 yields 1 error, I
can be 95% sure that the population deviation rate is no more than 4.7%" |
| 3) |
"If my sample of 125 yields 2 errors, I
can be 95% sure that the population deviation rate is no more than 4.9%" |
|
|
|
|
|
|
|
|
|
|
|
|