Consider the approximation. Use the central limit theorem to roughly estimate how big n must be so that we have 95% confidence that our computed approximation will be within .001 of the actual value. In developing your rough estimate, you should not use the actual value of , but you can use something like 3. How big must n be if we want to be within .0001? The ratio of areas is ((Pi*D*D)/4)/D*D)