Table 1.

Computed sample size, estimated power, and difference for the exact and approximate procedures with {β_I, β_S} = {4.1, 0.15}, {β_I0, β_S0} = {4.198, 0.143}, σ² = 0.095, μ_X = 24.2, ${\sigma }_X^2$ = 6, and Type I error α = 0.05

Nominal power	Exact approach		Approximate method		Difference
	N	Estimated power	N	Estimated power	N	Power
0.80	173	0.8001	183	0.8236	10	0.0235
0.90	227	0.9010	239	0.9161	12	0.0151