A radio station claims that the amount of advertising each hour has a mean of 13 minutes and a standard deviation of 1.8 minutes. You listen to the radio station for 1 hour and observe that the
Amount of advertising time is 8 minutes. Calculate the z-score for this amount of advertising time.
A)z = -9
B)z = 0.48
C)z = -2.78
D)z = 2.78

Question

Quizplus · Accepted Answer

The z-score is calculated using the formula $z = \frac{(X - \mu)}{\sigma}$, where $X$ is the observed value, $\mu$ is the mean, and $\sigma$ is the standard deviation. Plugging in the given values: $z = \frac{(8 - 13)}{1.8} = \frac{-5}{1.8} = -2.78$.

A Radio Station Claims That the Amount of Advertising Each