Use the interest formula (I = Prt) to determine the amount of interest earned, where the principle (P) is 4,000, the rate (r) is .03 (3%) and the time (t) is 10. I = 4,000(.03)(10), or I = 1,200.
Add the interest earned to the original amount invested. 4,000 + 1,200 = 5,200.