Answer:
4.7 ~~~ :D
Step-by-step explanation:
t = total...i = initial amount ridden......d = days..... m = average amount of miles
---------------
t = i +dm
26.8 = 8 + 4m
----------------- solve -----------------
26.8 = 8 + 4m ----> 18.8 = 4m ----> 4.7 = m