Pierre deposits $9,000 in a certificate of deposit that pays 8% interest, compounded semiannually. how much interest does the account earn in the first six months? what is the balance after six months?

P = $9,000, the principal
r = 8% = 0.08, the interest rate
n = 2, semiannual compounding

After 6 months, the interest is
9000 * 0.08 = $720
The balance after 6 months is
9000 + 720 = $9720

Answer
Interest = $720
Balance = $9,720