Joe’s annual income has been increasing each year by the same dollar amount. The first year his income was $19.400 and the 5th year his income was $23,800. In which year was his income $30,400?
we know the 1st year it was 19400 and by the 5th year, namely 4 years later, it was 23800, now the amount difference is 23800 - 19400 = 4400, 4400 over 4 years for a steady amount of 4400/4 = 1100 per year.
