Example 3) The table shows the amount y (in milligrams) of caffeine in a person's bloodstream x hours after drinking coffee. Write an exponential function that models the data. a) What is the percent growth/decay rate? Time, x & Caffeine, y 0 & 125 1 & 100 2 & 50 3 & 64 4 & 51 b) Predict the amount of caffeine in the person's bloodstream after 6 bours. Example 4) The table shows the value y of a car after x years. Year, x & 0 & 1 & 2 & 3 }(c) Value, y (dollars) & 15,000 & 13,950 & 12,973.50 & 12,065.36 a) Write an exponential equation that models the value of the car.