Returns the inverse of the cumulative NORM.DIST function. Given a probability, this function returns the value at which the cumulative normal distribution equals that probability. This is used to find thresholds: NORM.INV (0.95, 63, 5) NORM.INV (0,95; 63; 5) returns roughly 71.2, the value that 95% of a normal distribution with a mean of 63 and a standard deviation of 5 lies below.