1) Given the graph of f(x), estimate the following.
(a) Is the graph increasing or decreasing?
(b) Is this an example of exponential growth or exponential decay?
(c) Find f(-20)
(d) What x value will make f(x) = 80?
(e) Estimate the y-intercept.
2) Find an exponential model for the given data.
| x | f(x) |
| 0 | 12 |
| 1 | 60 |
| 2 | 300 |
| 3 | 1500 |
| 4 | 7500 |
3) Students in a chemistry class were asked to run an experiment that would simulate the decay of an imaginary element. The students were given 100 dice to roll all at once and after each roll they would remove any die that showed a 5 on top. The students in one group collected the following data.
| Number of Rolls | Remaining Dice |
| 0 | 100 |
| 1 | 84 |
| 2 | 70 |
| 3 | 56 |
| 4 | 48 |
| 5 | 42 |
| 6 | 34 |
| 7 | 28 |
Find an equation for a model of these data. (Use the first and last sets of data from the table to calculate your equation. Round your value of a to the nearest whole number and your value of b to three decimal places.)
4) Find the growth or decay rate of the given exponential model.
f(x) = 110(0.93)x
5) Karina has two investment options for $40,000 she is saving for her future college expenses. One account pays 3.3%interest compounded quarterly. The second account pays 3.2% compounded daily. Which account will have the larger balance after 3 years?
