1. Exponential Decay - decreases by a constant factor -decay factor (Mult.) - Less than 1 X Y 1100 220 34 d.f. = Y-int =

2. Decay Rate % data is decreasing by EXAMPLE If you are given the decay factor0.52 - Make a %52% - Subt from 100 = decay rate48% If you are given the decay rate87% - Subt from 10013 % - Make a decimal = decay factor.13

3. Exponential Decay X Y x y 0 3000 324 11801 108 2108 2 36DF =

4. Unit Review GGG

5. Round 1 The foundation of your house has about 1,200 termites. The termites grow at a rate of about 15% per day. 1.Growth Factor? 2. Write an equation

6. Round 2 1. How many termites will there be in 3 weeks? 2.When will there be 850,000 termites? y=1200(1.15 x )

7. Round 3 1. What is the decay rate? 2. What is the decay factor? Kristen saved $5000, but in order to pay bills she is spending her money at a rate of 40% of her savings per month.

8. Round 4 Kristen saved $5000, but in order to pay bills she is spending her money at a rate of 40% of her savings per month. Months01234 Current Balance

9. Round 5 Kristen saved $5000, but in order to pay bills she is spending her money at a rate of 40% of her savings per month. 1.Write an equation. 2. When will she run out of money?

10. The Easter bunny gave Tommy 5 jellybeans and sent him on a hunt for the rest. He finds 10 jellybeans per min. – What type of relationship is this? -Write an equation that represents the total number of jellybeans Tommy has.

11. Joey collected 85 jellybeans. He does not like the black jellybeans, so he threw them at his brother at a rate of 6 jellybeans per min. -Write an equation that represents how many jellybeans Joey has. -In 14 min, how many does Joey have left?

12. Round 6 Find the decay rate or factor 1. 20% 2.0.85 3.0.7 4.54%

13. Round 7 You drink a Pepsi that contains 120mg of caffeine. Each hour, the caffeine decreases by 12%. 1. What is the decay rate? 2. What is the decay factor? 3. Write an equation

14. Round 8 An adult takes 400 mg of ibuprofen. Each hour, the amount of ibuprofen in the person’s system decreases by about 29%. How much ibuprofen is left after 6 hours?

15. Round 9 You have inherited land that was purchased for $30,000 in 1960. The value of the land increased by approximately 5% per year. What is the approximate value of the land in the year 2011?