Chapter 6.2, Problem 52E

To determine

To Calculate: the mean for difference and explain it

Answer to Problem 52E

  $\mu =-4$

Explanation of Solution

Given:

  $\begin{array}{l}{\mu }_B=12\\ {\sigma }_B=4\\ {\mu }_W=16\\ {\sigma }_W=1\end{array}$

B= commute time by bus

W= commute time when talking

Calculation:

  $\begin{array}{c}\mu ={\mu }_B-{\mu }_W\\ =12-16\\ =-4\end{array}$

There are two mean of two different random variables ${\mu }_B=12$ and ${\mu }_W=16$ so the mean of the two random variable will be the difference of their means so the commute time by bus is average 4 minute lesser than the commute time when walking