A random sample of n = 4 scores is obtained from a normal population with µ = 20 and σ = 4.What is the probability that the sample mean will be greater than M = 22?
A)0.50
B)1.00
C)0.1587
D)0.3085

Question

A random sample of n = 4 scores is obtained from a normal population with µ = 20 and σ = 4.What is the probability that the sample mean will be greater than M = 22?​
A)​0.50
B)​1.00
C)​0.1587
D)​0.3085

Quizplus · Accepted Answer

The standard error of the mean (SEM) is σ/√n = 4/√4 = 2. The z-score for M = 22 is (22 - 20) / 2 = 1. Using the standard normal distribution table, the probability of a z-score greater than 1 is 0.1587.

A Random Sample of N = 4 Scores Is Obtained