The question is either poorly constructed or it is a trick question. We do not know "In what year was his income 30,300" because the years correlating to his income are not disclosed. Even assuming the question was meant to be posed as "how many years later was his income 30,300" it is still flawed.
Step-by-step explanation:
To arrive at Joe's annual income increase, first subtract 19,500 from 27,900 to get 8400, which is his overall increase over the 8 years. Now divide 8400 by 8. You will get 1050. Beginning with his income of 27,900, add 1,050 to each successive income amount and you will get the following progression:
