Figure 2. Geometric Interpretation of the Optimization Problem. The feasible region includes all possible combinations of the lower (θ_L) and upper (θ_H) limits of the confidence interval that will give at least the desired confidence level. The straight lines represent dent widths of the confidence interval. The interval with the minimum width is represented by the first of these lines to touch the feasible region, and in this case is the line where θ_H-θ_L=.3693. Lines below treat line are not feasible, and lines above it give a wider confidence interval. The numbers on this plot are shown for a desired confidence level of 95% for a Bernoulli parameter whir n = 20 and t_0= 4.