An athlete rides his bike 8 miles for every 3 miles that he runs. if the athlete runs 4.5 miles, how far does he ride his bike?

Given, 
Athlete rides bike for 8 miles if he runs 3 miles  
To find, 
How far will athlete ride if he runs 4.5 miles? 
 Solution: - From above situation we take miles for which athlete will ride bike = X

 Then the ratio will be 
 8:3 = x: 4.5
 8/3 = x/4.5
 Solving this will give 12.
 Hence, athlete will ride bike for 12 miles if the athlete runs 4.5 miles.

The answer to your question is b’(16,14)