Answer
The percentage of college students who sleep between
$5$ and $7$ hours is $=43\%$.
$9$ and $11$ hours is $=2\%$.
Work Step by Step
The total percentage of college students who sleep between $5$ and $7$ hours or between $9$ and $11$ hours is $45\%$.
From the graph we can write.
$\Rightarrow x+y=45$ ......(1)
Difference between $5$ to $7$ and $9$ to $11$ hours is equal to $41\%$.
From the graph $(x>y)$ we can write.
$\Rightarrow x-y=41$ ......(2)
Add equation (1) and (2).
$\Rightarrow x+y+x-y=45+41$
Add like terms.
$\Rightarrow 2x=86$
Divide both sides by $2$.
$\Rightarrow \frac{2x}{2}=\frac{86}{2}$
Simplify.
$\Rightarrow x=43$
Plug the value of $x$ into equation (1).
$\Rightarrow 43+y=45$
Subtract $43$ from both sides.
$\Rightarrow 43+y-43=45-43$
Simplify.
$\Rightarrow y=2$.
