Question

The 200 meter race times at a state track meet are normally distributed with a mean of 13.56 seconds and a standard deviation of 2.24 seconds. Using the standard normal probabilities table, what is the approximate probability that a runner chosen at random will have a 200 meter time less than 13.5 seconds?

A. 0.4880
B. 0.6331
C. 0.7422
D. 0.5714
E. 0.7910

Answer 1

0.4880 is the approximate probability

Answer 2

A. 0.4880

Explanation:

First, find the z-score:

z = (x − μ) / σ

z = (13.5 − 13.56) / 2.24

z = -0.03

Using a z-score table:

P(z < -0.03) = 0.4880