The sample mean and variance of N independent observations from a random variable x are,
Assumption: a normal distribution in x.
Confidence interval for mean value
where tn is Student-t statistic and n = N-1.
Or,
where,
Statistical convergence error of mean value
Confidence interval for variance value
where χn is chi-square statistic and n = N-1.
Or,
where
Statistical convergence error of variance is defined as