Question

The time that it took students to complete an obstacle course in Gym class follows a normal distribution.

The mean time is 21 minutes with a standard deviation of 4 minutes.

If Ashley's time to complete the obstacle course corresponds to a z-score of -1.2, how long did it take her to complete the course?

Enter your answer into the box below. Then use the drop-down menu to select the correct units.

Answer 1

Use x = μ + zσ.

x = 21 + (−1.2)(4) = 21 − 4.8 = 16.2

Answer: 16.2 minutes.