Power Curve (for the difference between two means)

Calculates the power curve (1-β for a difference in means μ1 - μ2). You can choose from three types of alternative hypotheses: that μ1 is greater than μ2, that μ1 is less than μ2, or that μ1 is equal to μ2, given the null hypothesis that μ1 and μ2 are equal.Enter the sample sizes n1 and n2, the significance level α, and the effect size Δ (defined as (μ1 - μ2) / σ—that is, how many times the standard deviation the difference in means is), along with the maximum and minimum values and the number of intervals, to generate a power curve graph.