A normal distribution has μ = 80 and σ = 10.What is the probability of randomly selecting a score greater than 90 from this distribution?
A)0.8413
B)0.1587
C)0.3085
D)0.6915

Question

Quizplus · Accepted Answer

To find the probability of a score being greater than 90 in a normal distribution with a mean (μ) of 80 and a standard deviation (σ) of 10, we first calculate the Z-score for 90. The Z-score is calculated as (X - μ) / σ = (90 - 80) / 10 = 1. A Z-score of 1 corresponds to the 84.13th percentile of a normal distribution, meaning 84.13% of values lie below 90. Therefore, the probability of a score being greater than 90 is 1 - 0.8413 = 0.1587.

A Normal Distribution Has μ = 80 and σ =