Table 2.

Sample size required per profession to detect a difference in proportion at α = .05

	Effect size
1-β	22% (28.0% vs. 50.0%)	25.5% (28.0% vs. 53.5%)	29% (28.0% vs. 57.0%)
.75	31	23	18
.80	35	26	20
.85	41	31	24