If one knows the mean, the raw score and the z score, then the z score equation can be used to calculate the standard deviation.

Question

Quizplus · Accepted Answer

The z score equation is z = (X - μ) / σ, where z is the z score, X is the raw score, μ is the mean, and σ is the standard deviation. Rearranging the equation to solve for σ gives σ = (X - μ) / z, allowing calculation of the standard deviation if the mean, raw score, and z score are known.

If One Knows the Mean, the Raw Score and the Z