Question

A radio station claims that the amount of advertising per hour of broadcast time has an average of 10 minutes and a standard deviation equal to 5 minutes. You listen to the radio station for 1 hour, at a randomly selected time, and carefully observe that the amount of advertising time is equal to 8.2 minutes. Calculate the z-score for this amount of advertising time. Round your answer to 2 decimal places.

Answer 1

Answer:   -0.36

Step-by-step explanation:

Given: Mean : $\mu=10\text{ minutes}$

Standard deviation : $\sigma=5\text{ minutes}$

We know that the formula to calculate the z-score is given by :-

$z=\dfrac{x-\mu}{\sigma}$

For x=8.2 minutes, we have

$z=\dfrac{8.2-10}{5}=0.36$

Hence, the z-score for this amount of advertising time = -0.36