Hi Engineering,

Let's start with adding up the fractions of inches. We have:
1/2, 1/4 and 5/8. The lowest common denominator is an eighth.

1/2 = x/8? Since 2 goes into 8 (4) times, 1/2 = 4/8
1/4 = x/8? Since 4 goes into 8 (2) times, 1/4 = 2/8

5/8 + 4/8 + 2/8 = 11/8 of an inch, which is 1 foot, 3/8 inches

Next, we can add the inches together: 3" + 2" + 7" + 1" (from the calculation we just did) = 13", which is 1 foot, 1 inch

Now, let's look at feet: 7' + 4' + 6' + 8' + 1' (from the calculation we just did) = 26'

And summing it all up we have: 26' 1 3/8"

Hope that helps!