Distance covered in first 3 days is, 5.3 + 6.5 + 6.2 = 18 miles.
Shannon's goal, T = 40 miles.
Number of remaining days, n = 7 - 3 = 4 days.
Number of miles left, 40 - 18 = 22 miles.
Now,
Number of miles per day she needed :
n = 22/4 = 5.5 miles /day
Therefore, he need to run 5.5 miles per day.
Hence, this is the required solution.