Suppose that the time that your employees spend reading and answering e-mail each day varies between 1.5 and 3.5 hours and is uniformly distributed over this range of values.Determine the standard deviation of the "time spent reading and answering e-mail" random variable.
A)0.33 hours
B)0.58 hours
C)33%
D)58%
E)75%

Question

Quizplus · Accepted Answer

The standard deviation ($\sigma$) of a uniformly distributed random variable over an interval $[a, b]$ is given by the formula $\sigma = \frac{b-a}{\sqrt{12}}$. Here, $a = 1.5$ hours and $b = 3.5$ hours, so $\sigma = \frac{3.5 - 1.5}{\sqrt{12}} = \frac{2}{\sqrt{12}} = \frac{2}{3.464} \approx 0.577$ or 0.58 hours.

Suppose That the Time That Your Employees Spend Reading and Answering