9.4 find the following values assuming a regular, or ordinary, annuity: a. The present value of $400 per year for 10 years at 10 percent b. The future value of $400 per year for 10 years at 10 percent c. The present value of $200 per year for 5 years at 5 percent d. The future value of $200 per year for 5 years at 5 percent please post the formula used for all questions