Review Session 3 Exponential Functions & Mixed.

1.The population of Bridgeville, PA, is 5,300 with a growth rate of 1.3% per year.Which expression could be used to estimate the population of Bridgeville t years from now?

1.1.3(5300)t

2.5300(1.3)t

3.5300(1.013)t

4.5300t1.3

2. The exponential function f(x) = 15,000(1.02)x models the amount of money in a savings account over a period of time.What does the value 15,000 represent?

  1. amount remaining in the account
  2. original amount in the account
  3. rate of growth
  4. time

3. Since January 1980, the population of the city of Brownville has grown according to the mathematical model y = 720,500(1.022)x, where x is the number of years since January 1980. Which statement about this mathematical model is true?

  1. 720,500 represents the population in 1980, while the 1.022 represents a growth rate of 22% added to the current population.
  2. 720,500 represents the population in 1980, while 1.022 represents a growth rate of .22% added to the current population.
  3. 720,500 represents the population in 1980, while 1.022 represents a growth rate of 2.2% added to the current population.
  4. 720,500 represents the population in 1980, while 1.022 represents a growth rate of .022% added to the current population.

4.Which exponential equation models the data from the table below?

  1. y = 4(2)x
  2. y = 2(4)x
  3. y = 8(2)x
  4. y = –4(2)x

5. Sketch the functions below and name each?

6.Write an exponential regression function from the given graph.

7.The population of a small town has been gradually decreasing over the past number of years. The equation: A = 1236(.97)t, where t is time in years, how many years does it take for the population to reach 500? Show a well labeled sketch with an appropriate window.

8. The parents of twin boys started a college fund when the boys were 5 years old.They decided to invest $6,000 into an account that compounds quarterly at a rate of 8.6% annually. If the parents do not invest any additional money into this fund, how much will each of the boys have toward his education when they reach 18 years old?

Use the formula: , whereA is the amount at the end of a specific length of time, P is the initial amount of the investment, ris the rate as a decimal and t is time.Round your answer to the nearest cent.

9. The flight paths of two Thunderbird jets are plotted on a Cartesian coordinate plane, and the equations of the jets’ flight paths are represented by y = 2x+ 3 and y = 0.5x. The best approximation of the intersection of the flight paths is

  1. (-1.72,3.3)
  2. (0,1)
  3. (-1.50,2.82)
  4. (-2,-1)

10) Mixed it UP.

The data in the two-way table shows the results to a survey given to a group of students.

Which statement about the data in the two-way table is most accurate?

  1. About 50% of the students have a pet.
  2. About 75% of students who average over an hour of daily activity have a pet.
  3. About 60% of students who average less than an hour of daily activity do not have a pet.
  4. About 45% of students average less than an hour of daily activity.

11.

Use the plot below that shows length of the toys that the students of Mr. West's 4th grade students brought to class.

What is the difference in length between the longest toy and the shortest toy?

  1. cm
  2. 3 cm
  3. cm
  4. 5 cm

12.

PART A:

The formula for the area of a trapezoid is A = h(b1+ b2). Express b1 in terms of A, h, and b2.

PART B:

The area of a trapezoid is 60 square feet, its height is 6 ft, and one base is 12 ft. Find the number of feet in the other base.

13. . Guy and Jim work at a furniture store. Guy is paid $185 per week plus 3% of his total sales in dollars, x, which can be represented by g(x) = 185 + 0.03x. Jim is paid $275 per week plus 2.5% of his total sales in dollars, x, which can be represented by f(x) = 275 + 0.025x. Determine the value of x, in dollars, that will make their weekly pay the same.