8 Aug, 13 | by Bob Phillips

As mentioned in previous posts, part of the joys of playing with numbers is in making inferences about how the future will be. This is often why you’re looking for a confidence interval, showing (sort of) where the truth lies with 95% certainty.

How you build these CI is interesting.

One way is to assume a Normal distribution exists, and then the sample size and sample mean will give you the CI (using the standard error of the mean). If you’re not quite sure that it really is a Normal distribution, then you have a range of opportunities, one of which is a bit 50 shades of starts: bootstrapping. more…