The computation of a confidence interval on the population value of Pearson's correlation (ρ) is complicated by the fact that the sampling distribution of r is not normally distributed. The...The computation of a confidence interval on the population value of Pearson's correlation (ρ) is complicated by the fact that the sampling distribution of r is not normally distributed. The Z for a 95% confidence interval (Z0.95) is 1.96, as can be found using the normal distribution calculator (setting the shaded area to 0.95 and clicking on the "Between" button).