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Subsection 2.3 Comparing Linear and Exponential Models Exercises

  1. Refer to the population of Las Vegas, NV, for given years as shown in TableΒ 2.3.15.
    Table 2.3.15. Population, \(P(t)\text{,}\) of Las Vegas \(t\) years after 1980
    \(t\) 0 10 20 30
    \(P(t)\) 164,674 259,834 484,487 583,756
    1. Using the population of Las Vegas in 1980 and 2010, build an exponential model for \(P(t)\text{.}\)
    2. Use your exponential model to predict the population of Las Vegas in 1990. How does your prediction compare with the actual population at that time?
    3. Use your exponential model to predict in what year the population of Las Vegas will be 600,000.
    4. Using the population of Las Vegas in 1980 and 2010, build a linear model for \(P(t)\text{.}\)
    5. Do you think the linear model or the exponential model is a better fit to the data? Explain.
    6. What could happen in the future that would make the model fail?
  2. The town of Allen had a population of 36,000 in 1980, and has been growing at 2.2% per year. The town of Berry had a population of 44,200 in 1980, and a population of 48,000 in 1990.
    1. Find an exponential model, \(A(t)\text{,}\) for the population of Allen \(t\) years after 1980.
    2. Find an exponential model, \(B(t)\text{,}\) for the population of Berry \(t\) years after 1980.
    3. When did the population of Allen reach 45,000?
    4. When did the population of Allen equal the population of Berry?
    5. What is the average number of people added to Allen between 1980 and 2000?
  3. The owners of a movie theater know that the number of people who attend is a function of the price of the tickets. The theater has a capacity of 240 people. If tickets are sold for $1, the theater will fill up completely. On the other hand, if the theater charges $21/ticket, no one will buy tickets.
    1. Assuming that the number of tickets sold, \(S(t)\) is a linear function of the price, \(t\text{,}\) write an equation for \(S(t)\text{.}\)
    2. At what price will the theater fill 150 seats?
  4. A baseball is launched into the air from a height of \(2\) meters and with an initial upward velocity of \(25\) meters/second. The ball’s height above ground is given by the equation \(H(t)=-4.9t^2 + vt + h\text{,}\) where \(H\) is in meters and \(t\) is in seconds.
    1. Write an equation to model the height of a ball.
    2. How long is the ball in the air?
    3. What is the maximum height reached by the ball?
    4. On what interval is the height of the ball increasing?