Answer:
12 3/4 miles
Explanation:
Eric is increasing his distance by 2 3/8 miles per day. In 2 more days, his distance will be 2×(2 3/8) = 4 3/4 miles more than on Wednesday.
... 8 + 4 3/4 = 12 3/4 . . . . miles on Friday
_____
Rate of increase
The difference between Tuesday and Monday is ...
... 5 5/8 - 3 2/8 = 2 3/8
The difference between Wednesday and Tuesday is ...
... 8 - 5 5/8 = 2 3/8
Thus, it appears that Eric is jogging 2 3/8 mile more each day than the day before.