Answer:
Greg's average balance last month was $ 1,600.
Explanation:
Given that Greg's average balance checking account pays simple interest of 5.4% annually, and I have made $ 7.20 in interest last month, to determine what was Greg's average balance last month the following calculation must be performed:
5.4 / 12 = 7.20
100 = X
0.45 = 7.20
100 = X
100 x 7.20 / 0.45 = X
720 / 0.45 = X
1600 = X
Therefore, Greg's average balance last month was $ 1,600.
