Adam scored 45 on his final exam.His class's average score was 50, with a standard deviation of 10.What is Adam's z score?
A) -1
B) -0.5
C) 0.5
D) 1.5

Question

Quizplus · Accepted Answer

z score is calculated using the formula:
z = (x - μ) / σ

Where x is the raw score, μ is the mean and σ is the standard deviation.

In this question:
x = 45 (Adam's score)
μ = 50 (Class average)
σ = 10 (Standard deviation)

Plugging these values into the formula:
z = (45 - 50) / 10
z = -0.5

Therefore, Adam's z score is -0.5, which is closest to answer choice B (-0.5).

Adam Scored 45 on His Final Exam