Subtract the mean from the value
Divide the result by the standard deviation
Use the formula: z = (x – μ) / σ
For a sample, use: z = (x – x̄) / s
Identify x as the data value
Identify μ as the population mean
Identify σ as the population standard deviation
Identify x̄ as the sample mean
Identify s as the sample standard deviation
Compute the difference between the value and the mean
Divide by the appropriate spread measure
Interpret the result as the number of standard deviations from the mean