Answer:
216.5 miles per hour.
Step-by-step explanation
This is a fraction equal to
866 miles ÷ 4 hours
We want a unit rate where
1 is in the denominator,
so we divide top and bottom by 4
866 miles ÷ 4
4 hours ÷ 4
=
216.5 miles
1 hour
=
216.5 miles
hour