If you would like to know what percent of earnings did Jon pay in entertainment expenses, you can calculate this using the following steps:
x% of $38000 is $6840
x% * 38000 = 6840
x/100 * 38000 = 6840
x * 380 = 6840 /380
x = 6840 / 380
x = 18%
The correct result would be 18%.