Answer
$183.3 \ ft$
Work Step by Step
Let $C$ be the circumference of a circle:
$C=2 \pi r$ or, $C=\pi d~~~~(1)$
Here, $r$ represents radius and $d$ is diameter.
We are given that $d= 7 \ in.$
So, $C= \pi (7)=7 \pi \ in.$
In feet, we have $C=7 \pi \ in. \times \dfrac{1 ft}{12 in.}=\dfrac{7 \pi}{12} \ ft$
In order to complete $100$ revolutions, the distance traveled by the hamster is:
$D=\dfrac{7 \pi}{12} \ ft (100)=183.3 \ ft$