if we imagine a line started from x1 and ends with x2
we have $\displaystyle \mu$ in the middle
what this $\displaystyle \mu$ represents?
does $\displaystyle \mu$ equals EX
?
$\displaystyle \mu$ if it is exactly halfway between $\displaystyle x_1$ and $\displaystyle x_2$ will be the average of the two values $\displaystyle x_1$ and $\displaystyle x_2$ or the mean, or in probability terms E(X) for certain cases.