To figure out this problem, let's set up an equation first to make it easier:
702.50 = 5.5x + 70
x = amount charged per hour
702.50 = 5.5x + 70
-70 -70
-----------------------------
632.5 = 5.5x
/5.5 /5.5
--------------------
115 = x
Owen was charged $115 per hour