Figure 2.

Behaviors of the ratio of the required sample size calculated by the normal approximation (N_AN) to that by the Monte-Carlo simulation-based approach, with correlation ρ¹² =0.0, 0.3, 0.5, 0.8 and 0.99 in the cases of R₁ =0.8, 0.7, 0.6, 0.5 and 0.4 with P_C1 =0.5, 0.2, 0.10 and 0.05, R₁ = R₂ = R and p_C1 = p_C2 = p_C, and equally sized groups (r =0.5) for K =2, with the desired overall power of 1 − β =0.80 for a one-sided test at the significance level of α =0.025.