
Originally Posted by
Soroban
Hello, vaironxxrd!
Graph the information on a number line.
. . $\displaystyle \begin{array}{c} w \\ -- \; \overbrace{\bullet \; ----- \; \bullet} \; -- \\ \underbrace{2.75 \qquad\qquad\quad 3.15}_{\text{average 2.95}} \end{array}$
$\displaystyle w\text{ is in the interval }[2.75,\:3.15]$
$\displaystyle \text{The midpoint of the interval is: }\:\tfrac{2.75 + 3.15}{2} \:=\:2.95$
$\displaystyle \text{Hence, }w\text{ is within 0.2 lbs of the midpoint.}$
$\displaystyle \begin{array}{ccccccc}\text{Therefore:} & \text{-}0.2 & \le & w-2.95 & \le & 0.2 \\ \\[-3mm] &&& |w-2.95| &\le & 0.2 \\ \\[-3mm] &&& |w-2.95| & < & 0.2 & \text{ ... answer (B)}\end{array}$