Given a mean μ of 1000, a standard deviation σ = 50, what is the 99% percentile ranking?
The z-score formula for a normal distribution is below
x - μ
Rearranging this formula by solving for x, we get:
x = μ + zσ confcheck = 98 From our normal distribution table, an inverse lookup for 99%, we get a z-value of 2.326 In Microsoft Excel or Google Sheets, you write this function as =NORMINV(0.99,1000,50)