FreeCalc sample size estimation						
						
						
Inputs						
Test sensitivity	0.975					
Test specificity	0.995					
Population size	1000					
Design prevalence	0.2					
Diseased elements	200					
Analysis method	Modified hypergeometric exact					
Target Type I error	0.05					
Target Type II error	0.05					
Population threshold for infinite probability formula	10000					
Maximum sample size	3200					
						
Results						
Required sample size:	22					
Cut-point number of reactors:	1					
Type I error:	0.0474					
Type II error:	0.0054					
Herd-level sensitivity:	0.9526					
Herd-level specificity:	0.9946					
Interpretation:	If a random sample of 22 units is taken from a population of 1000 and 1 or fewer reactors are found, the probability that the population is diseased at a prevalence of 0.2 is 0.0474.					
Method:	Modified hypergeometric exact					
						
Detailed Results						
1	1	0.199	0.995	0	0.801	0.005
2	100	1	0.9859	2	0	0.0141
3	2	0.3585	0.99	0	0.6415	0.01
4	3	0.4864	0.9851	0	0.5136	0.0149
5	4	0.5889	0.9801	0	0.4111	0.0199
6	5	0.671	0.9752	0	0.329	0.0248
7	6	0.7368	0.9704	0	0.2632	0.0296
8	7	0.7895	0.9655	0	0.2105	0.0345
9	8	0.8317	0.9607	0	0.1683	0.0393
10	9	0.8654	0.9559	0	0.1346	0.0441
11	10	0.8924	0.9511	0	0.1076	0.0489000000000001
12	11	0.6763	0.9987	1	0.3237	0.00129999999999997
13	12	0.7239	0.9984	1	0.2761	0.00160000000000005
14	13	0.7654	0.9981	1	0.2346	0.00190000000000001
15	14	0.8015	0.9978	1	0.1985	0.00219999999999998
16	15	0.8325	0.9975	1	0.1675	0.00249999999999995
17	16	0.8592	0.9971	1	0.1408	0.00290000000000001
18	17	0.8819	0.9968	1	0.1181	0.00319999999999998
19	18	0.9012	0.9964	1	0.0988	0.00360000000000005
20	19	0.9175	0.996	1	0.0825	0.004
21	20	0.9313	0.9955	1	0.0687	0.00449999999999995
22	21	0.9429	0.9951	1	0.0571	0.00490000000000002
23	22	0.9526	0.9946	1	0.0474	0.00539999999999996