Question

On a standardized exam, the scores are normally distributed with a mean of 450 and a standard deviation of 25. Find the z-score of a person who scored 435 on the exam.

Answer 1

z = (x − μ)/σ = (435 − 450)/25 = −15/25 = −0.6

So the score is 0.6 standard deviations below the mean.