Lesson 8

1. Lesson 8 Section two

2. Complete the following questions. Use your notes from lesson 8 – exponential growth and decay. Continue to write your answers on the answer sheet from lesson 8 – section 1.

3. GROWTH When the amount increases by the same percent for each time period A = I ( 1 + r ) t DECAY When the amount decreases by the same percent for each time period A = I ( 1 -r ) t Exponential Growth and Decay

4. QUESTIONS: 1. What are the formulas for exponential growth and decay?

5. Using the exponential formulas, what does 1 + r or 1 –r become for each problem below?: 2. A $10,000 investment decreased by 3% each year for 5 years. 3. A city population of 200,000 increases 4% each year for 10 years.

6. Complete the following questions below. Decide which formula to use: simple interest, compound interest, exponential growth or decay. 4.Jessica deposits $4,000 in a savings account that pays interest at 6.5% a year. How much will the investment accumulate to after 1 year? 5. $7,563 is invested at 6.2% compounded annually for 10 years. How much money will the investment yield after 10 years? Round to the nearest penny.

7. Find the yield, to the nearest penny, of each investment: 6. A principal of $20,000 is invested at 6% compounded annually for 4 years. 7. A principal of $40,000 is invested at 4.9% compounded annually for 5 years. 8. A principal of $35,000 is invested at 4.5% compounded annually for 4 years.

8. Solve. Round answers to the nearest whole number. 9. A business earned $200,000 in 1997. If it is predicted that the earnings will increase by 3% every year, predict the earnings at the end of 10 years. 10. A biologist discovers that a certain bacteria has a growth rate of 4% every hour. There are currently 15,000 bacteria. Predict the number at the end of 6 hours.

9. Your homework is a worksheet. Complete all of the problems.