Unit Review

Solve: 10/x=2

x = 5

Pherris is graphing the function f(x) = 2(3)x. He begins with the point (1, 6). Which could be the next point on his graph?

(2, 18)

Tanisha is graphing the function f(x) = 25(3/5)x. She begins by plotting the point (1, 15). Which could be the next point she plots on the graph?

(2, 9)

Nancy created a graph to predict the pay she will take home after taxes are taken from her income. Using the information on the graph, what is the constant of proportionality?

0.8

Brian can type 1 1/3 pages every 20 minutes. How many pages can he type in 2.5 hours?

10 pages

Rosa earns $12 per hour. In 7.5 hours, she will earn x dollars. Which is a valid proportion that can be used to solve the problem?

12/1=x/7.5

The weight of a person on or above the surface of the earth varies inversely as the square of the distance the person is from the center of the earth. A particular person weighs 179 pounds on the surface of the earth and the radius of the earth is 3900 miles. Determine the equation that relates weight, W, to the distance from the center of the earth, d, for this person.

2,722,590,000/d^2

The intensity of a radio signal from the radio station varies inversely as the square of the distance from the station. Suppose intensity is 8000 units at a distance of 2 miles. What will the intensity be at a distance of 12 miles? Round your answer to the nearest unit.

222 units

Mike and Julie surveyed students to determine how many had a grade of A in math. They recorded their findings for each survey in the table below. What is the constant of proportionality of the ratio of students surveyed to the number of A grades?

5

Enjoli is making cupcakes for a party. She needs 45 cupcakes but the recipe makes 15.

C

Which function represents exponential growth?

f(x) = 3x

The function f(x) = 5(1/5)x is reflected over the y-axis. Which equations represent the reflected function? Check all that apply.

f(x) = 5(1/5)-x f(x) = 5(5)x

Which function represents exponential decay?

f(x)= 4 (2/3)^x