The problem asks to find Raul's speed in miles per hour, given that he biked 8 miles in $\frac{4}{5}$ of an hour.

The formula for speed is:

$\text{Speed} = \frac{\text{Distance}}{\text{Time}}$

In this case, the distance is 8 miles, and the time is $\frac{4}{5}$ of an hour. The unit rate is found by dividing the distance by the time:

$\text{Speed} = \frac{8}{\frac{4}{5}} = 8 \times \frac{5}{4} = \frac{8 \times 5}{4} = \frac{40}{4} = 10 \, \text{miles per hour}.$

Thus, Raul's speed is 10 miles per hour.

Would you like more details on how this was calculated or have any questions?

Here are 5 related questions to expand your understanding:

1. If Raul biked 12 miles in $\frac{3}{4}$ hour, what would his speed be?
2. How would the speed change if the time increased to 1 hour but the distance stayed the same?
3. What is the meaning of a unit rate in the context of this problem?
4. Can the unit rate ever be a decimal, and how would you convert it from a fraction?
5. How would Raul's speed be affected if the distance were halved but the time remained the same?

Tip: When dividing by a fraction, multiply by its reciprocal to simplify the calculation.