Answer
$x ̅=139.2$
$E=13.4$
Work Step by Step
The point of estimate, $x ̅$, lies in the center of the confidennce interval: $\frac{125.8+152.6}{2}=139.2$
The margin of error, $E$, is the difference between the upper bound and the point estimate (or between the point estimate and the lower bound):
$152.6-139.2=139.2-125.8=13.4$
