Question

A runner's distribution of times for running 1,000 meters has a mean of 4.5 minutes with a standard deviation of 0.75 minutes. One of the runner's times has a z-score of –1.76. What is the runner's time?

Answer 1

3.18

Explanation:

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Answer 2

The runner’s time is 3.18 minutes

Explanation:

Mathematically;

z-score = (x-mean)/SD

In this question, we have the z-score but we want to calculate x

From the question

z-score = -1.76

mean = 4.5 minutes

SD = 0.75 minutes

x = ?

Substituting these values, we have that

-1.76 = (x-4.5)/0.75

0.75(-1.76) = x - 4.5

-1.32 = x - 4.5

x = 4.5 -1.32

x = 3.18