Your friend is taking a class called Math for Everyday Living at another college. He (or she) is learning about compound interest, and his instructor simply gave the class the compound interest formula, A=P(1+r/n)nT without explaining how it is gotten. When your friend told you this in a letter, you were shocked! Write a letter to your friend (no longer than two pages) that explains step-by-step how the compound interest formula is gotten.