On a standardized exam, the scores are normally distributed with a mean of 40 and a standard deviation of 10. Find the z-score of a person who scored 25 on the exam.

Answer 1

To find the z-score, we use the formula:

z = (x - μ) / σ

Where:
z = z-score
x = individual score (25 in this case)
μ = mean (40)
σ = standard deviation (10)

Plugging in the values:

z = (25 - 40) / 10
z = (-15) / 10
z = -1.5

Therefore, the z-score of a person who scored 25 on the exam is -1.5.