Acollege graduate expects to earn a salary of $55,000 during the first year after graduation and receive a 4% raise every year after that. what's the total income he will receive after ten years?

So we know that

Year 1 = $55,000
Year 2 = 55000 + (55,000 x .04) = 55000 + 2200 = $57,200
Year 3 = 57200 + (57200 * .04) = 57200 + 2288 = $59,488
Year 4 = 59488 + (59488 * .04) = 59488 + 2379.52 = $61,867.52
Year 5 = 61867.52 + (61867.52 * .04) = 61867.52 + 2474.70 = $64,342.22
Year 6 = 64342.22 + (64342.22 * .04) = 64342.22 + 2573.69 = $66,915.91
Year 7 = 66915.91 + (66915.91 * .04) = 66915.91 + 2676.63 = $69,592.54
Year 8 = 69592.54 + (69592.54 * .04) = 69592.54 + 2783.70 = $72,376.24
Year 9 = 72376.24 + (72376.24 * .04) = 72376.24 + 2895.05 = $75,271.29
Year 10 = 75271.29 + (75271.29 * .04) = 75271.29 + 3010.85 = $78,282.14

So by the tenth year following graduation, the student would be making $78,282.14 a year. If you add up all of the values (Year 1 thru Year 10) you get a total income over ten years of $660,355.86