Answer:The Average Rate Matt ran = 10 1/2 miles per hour
Explanation:
Matt's average rate, in miles per hour is referred to as Average Speed which is given as
Average Speed =Distance /Time
Distance for the first part of journey = 3 1/2 miles
Time = 1/3 hour
Average Rate ( Speed) = 3 1/2 miles ÷ 1/3
= 7/2 ÷ 1/3
= 7/2 x 3/1
= 21/2 = 10 1/2 miles per hour .