Answer: The required ratio would be 3 miles : 4 minutes.
Explanation:
Since we have given that
Speed of a cheetah = 45 miles per hour
So, it means
Distance = 45 miles
Time = 1 hour = 60 minutes
So, the ratio of the distance it travels to the time it takes would be
Distance : Time

Hence, the required ratio would be 3 miles : 4 minutes.