Bob worked 8.5 hours and earned $102. At that rate, how much will Bob earn if he works 19 hours.

If Bob worked 8.5 hours and earns $102 you divide 102 by 8.5 you get 12. So he gets paid 12 dollars / hour. So multiply 19 by 12 you get 228. Bob will make $228 if he works 19 hours.