If the mean score on a one mile running test was 14 minutes and the standard deviation was 1 minute what percentage of subjects ran the mile in 15 minutes or less

To find the percentage of subjects who ran the mile in 15 minutes or less, we need to calculate the area under the normal distribution curve up to 15 minutes.

First, let's determine the z-score of 15 minutes using the formula z = (x - μ) / σ, where x is the value (15 minutes), μ is the mean (14 minutes), and σ is the standard deviation (1 minute).

z = (15 - 14) / 1 = 1

Next, we need to determine the area to the left of the z-score of 1 on the standard normal distribution curve (also known as the z-table).

Using the z-table, we can look up the corresponding area. The area to the left of z = 1 is approximately 0.8413, or 84.13%.

This means that approximately 84.13% of subjects ran the mile in 15 minutes or less.