You heard that the average number of years of experience among stockbrokers is 14 years.You can't remember the standard deviation somebody with 8 years' experience has a z-score of -2.Find the standard deviation.
A)3 years
B)9 months
C)6 months
D)9 years
E)3 months

Question

Quizplus · Accepted Answer

The z-score formula is $Z = \frac{(X - \mu)}{\sigma}$, where $X$ is the value, $\mu$ is the mean, and $\sigma$ is the standard deviation. Plugging in the values, $-2 = \frac{(8 - 14)}{\sigma}$, solving for $\sigma$ gives $\sigma = 3$ years.

You Heard That the Average Number of Years of Experience