For a normally distributed population with a given mean (μ) and standard deviation (σ), this calculator finds the value that is needed to be at the xth percentile or higher.
For example, suppose the scores on a certain test are normally distributed with a mean of 85 and a standard deviation of 4. We want to know what score a student needs to receive in order to have a higher score than 95% of all other students. This calculator will allow us to find that score.
To find the cut off value for a given population mean, population standard deviation, and percentile, simply fill in the necessary values below and then click the “Calculate” button.
A value of 91.57941 is needed to be above 95% of all other values.
z = (X – μ) / σ
1.64485 = (X – 85) / 4
1.64485 * 4 = X – 85
(1.64485 * 4) + 85 = X
91.57941 = X