The distribution of sample means for scores on a test for samples of size 100 is normal with a mean of 61.7 and a standard deviation of 1.5. If a sample of 100 test scores is selected at random, what is the probability that the sample mean will be greater than 63.8?
A)0.9192
B)0.0668
C)0.0808
D)1.4

Question

Quizplus · Accepted Answer

The probability can be found using the standard normal distribution (Z-score). The Z-score is calculated as (63.8 - 61.7) / 1.5 = 1.4. Using a Z-table, the probability of a Z-score greater than 1.4 is approximately 0.0808.

The Distribution of Sample Means for Scores on a Test