FreeCalc sample size estimation						
						
						
Inputs						
Test sensitivity	0.9					
Test specificity	0.95					
Population size	1,00E+06					
Design prevalence	0.2					
Diseased elements	2,00E+05					
Analysis method	Simple binomial (large population)					
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:	39					
Cut-point number of reactors:	4					
Type I error:	0.0493					
Type II error:	0.0438					
Herd-level sensitivity:	0.9507					
Herd-level specificity:	0.9562					
Interpretation:	If a random sample of 39 units is taken from a population of 1e+06 and 4 or fewer reactors are found, the probability that the population is diseased at a prevalence of 0.2 is 0.0493.					
Method:	Simple binomial (large population)					
						
Detailed Results						
1	1	0.22	0.95	0	0.78	0.05
2	100	0.9995	0.9718	9	5,00E-04	0.0282
3	2	0.0484	0.9975	1	0.9516	0.00249999999999995
4	3	0.1239	0.9928	1	0.8761	0.00719999999999998
5	4	0.2122	0.986	1	0.7878	0.014
6	5	0.3041	0.9774	1	0.6959	0.0226
7	6	0.3937	0.9672	1	0.6063	0.0328
8	7	0.4775	0.9556	1	0.5225	0.0444
9	8	0.2486	0.9942	2	0.7514	0.00580000000000003
10	9	0.3158	0.9916	2	0.6842	0.00839999999999996
11	10	0.3831	0.9885	2	0.6169	0.0115
12	11	0.4488	0.9848	2	0.5512	0.0152
13	12	0.5114	0.9804	2	0.4886	0.0196
14	13	0.5699	0.9755	2	0.4301	0.0245
15	14	0.6239	0.9699	2	0.3761	0.0301
16	15	0.6731	0.9638	2	0.3269	0.0362
17	16	0.7173	0.9571	2	0.2827	0.0429
18	17	0.5333	0.9912	3	0.4667	0.00880000000000003
19	18	0.5825	0.9891	3	0.4175	0.0109
20	19	0.6285	0.9868	3	0.3715	0.0132
21	20	0.6711	0.9841	3	0.3289	0.0159
22	21	0.7102	0.9811	3	0.2898	0.0189
23	22	0.7458	0.9778	3	0.2542	0.0222
24	23	0.7779	0.9742	3	0.2221	0.0258
25	24	0.8067	0.9702	3	0.1933	0.0298
26	25	0.8324	0.9659	3	0.1676	0.0341
27	26	0.8552	0.9613	3	0.1448	0.0387
28	27	0.8753	0.9563	3	0.1247	0.0437
29	28	0.8929	0.9509	3	0.1071	0.0491
30	29	0.7967	0.9864	4	0.2033	0.0135999999999999
31	30	0.8213	0.9844	4	0.1787	0.0155999999999999
32	31	0.8434	0.9821	4	0.1566	0.0179
33	32	0.8631	0.9796	4	0.1369	0.0204
34	33	0.8808	0.977	4	0.1192	0.023
35	34	0.8964	0.9741	4	0.1036	0.0259
36	35	0.9103	0.971	4	0.0897	0.029
37	36	0.9225	0.9676	4	0.0775	0.0324
38	37	0.9332	0.9641	4	0.0668	0.0359
39	38	0.9425	0.9603	4	0.0575	0.0397
40	39	0.9507	0.9562	4	0.0493	0.0438