Answer
The spring is stretched between 20 and 32 inches.
Work Step by Step
Write an equation for d.
$\frac{d}{F}=0.8\longrightarrow$ multiply each side by F
$\frac{d}{F} \times F=0.8F\longrightarrow$ multiply
$d=0.8F$
Substitute the upper and lower quantities for F to find the range for d.
$0.8(25)\leq d\leq0.8(40)\longrightarrow$ multiply
$20\leq d \leq32$
