Question

Assume that 1,500,000 people take the ACT each year and their scores form a normal distribution. If Susan scores one standard deviation below the mean, what percentile is she?

Answer 1

Susan's score is around the 15.87th percentile.

Step-by-step explanation:

To find the percentile of Susan's score, we need to calculate the z-score. The z-score is a measure of how many standard deviations her score is away from the mean. Since Susan's score is one standard deviation below the mean, her z-score is -1.

Using a z-score table or a calculator, we can find that approximately 15.87% of the scores fall below a z-score of -1. Therefore, Susan's score is around the 15.87th percentile.