Answer:
3.93 per hour
Explanation:
The first 4 hours is at 20 hours / 4 hours or 5 dollars an hours
The second line has a slope of 2.50 dollars an hour
But there is also a surcharge when you go over 4 hours
That is a 5 dollar flat rate at 4 hours
Assuming that we do not include the flat rate in the hourly calculation
4 hours * 5 dollar + 3 hours * 2.50 = 20+7.50
27.50 is the hourly charge
Divide by 7 hours
3.928571429
3.93 per hour