We are given a right triangle $\triangle WXY$ with $\angle W = 90^\circ$, $WY = 5$, and $\angle Y = 50^\circ$. We want to find the length of side $XY$.
We can use the trigonometric ratio involving the adjacent side ($WY$) and the hypotenuse ($XY$) with respect to the given angle $\angle Y$. The cosine function relates these sides and the angle:
$\cos(Y) = \frac{\text{adjacent}}{\text{hypotenuse}} = \frac{WY}{XY}$
Substituting the given values, we have:
$\cos(50^\circ) = \frac{5}{XY}$
To solve for $XY$, we can multiply both sides by $XY$ and then divide both sides by $\cos(50^\circ)$:
$XY \cdot \cos(50^\circ) = 5$
$XY = \frac{5}{\cos(50^\circ)}$
Now, we can use a calculator to find the value of $\cos(50^\circ)$ and then calculate $XY$:
$XY \approx \frac{5}{0.6428} \approx 7.7786$
Rounding to the nearest hundredth, we get $XY \approx 7.78$.