Answer:
53.2 mph
Explanation:
Mara's family travels 239.4 miles between the hours of 9:10 a.m. to 1:40 p.m.
1:40 p.m. is 13:40.
Thus, they traveled for
13 hours 40 minutes - 9 hours 10 minutes = 4 hours 30 minutes
that is
hours.
Use formula:

where
D = distance
r = rate
t = time.
In your case,
D = 239.4 miles
t = 4.5 hours
Hence,
