Excel template that automatically logs timed values, calculates a 95% confidence interval around your average, and the number of samples required to achieve a desired confidence interval.

It is counterintuitive that, with a sample of only one value from a normal distribution, one can construct a finite confidence interval of any size for the mean. It goes just as much against standard ...

In this note, in which we concentrate on two-sided intervals, this suggestion is examined, as is the effect of uncertainty in our knowledge of the population variance σ 2 on estimates of sample size.