If he earned $404.70 per 19 hours, you do 404.70/19 to figure out the amount he earns per hour. 404.7/19 is 21.3. He earns $21.3 per hour. to solve, you find how many times 21.3 goes into 617.7 or 617.7/21.3. That is 29. He needs to work 29 hours to earn $617.70