Subtract the mean from the value: (x – mu)
Divide the result by the standard deviation: (z = frac{x – mu}{sigma})
Use the sample mean and sample standard deviation if working with a sample: (z = frac{x – bar{x}}{s})
Identify the value (x)
Identify the mean (mu) or (bar{x})
Identify the standard deviation (sigma) or (s)
Plug the values into the formula
Compute the result
Interpret the sign: positive means above the mean, negative means below the mean