Proportional Relationships & Constants of Proportionality

y is directly proportional to x, and y = 30 when x = 6.

What is the value of y when x = 7?

• 30

• 35

• 25

• 36

Is the graph proportional, inversely proportional or neither?

• Inversely Proportional

• Proportional

• Neither

Which Graph is inversely proportional?

• Graph B

• Graph C

• Graph A

• None

Which answer best describes this graph?

• nonlinear and nonproportional

• linear and nonproportional

• linear and proportional

• nonlinear and proportional

Which option best describes a proportional relationship? Circle all that apply.

• The line goes through the origin, (0,0).

• A proportional relationship has a downward curving slope.

• The point (1,k) is a solution to a proportional relationship.

• None are correct.

What is the rate of change for the following graph?

*Hint: you can make a table with your input and output. Or you can use the equation y = kx to solve for your constant.

• 16

• 1

• 8

• 2

A climber is on a hike. After 3 hours he is at an altitude of 500 feet. After 6 hours, he is at an altitude of 800 feet. What is the average rate of change?

• 300

• 3

• 100

• 6

Find the rate of change (or constant), and solve for the missing output.

• 27

• 72

• 90

• 88

y in inversely proportional to x, and y = 9 when x = 4.

What is the value of y when x = 3?

*Remember the formula for inverse relationships is y = k/x

• 12

• 4

• 36

• 9

Susan and Joe both insure their properties with the Oklahoma Insurance Company. The cost of house insurance premiums with the Oklahoma Insurance Company is directly proportional to the value of the property being insured.

Susan pays premiums of $80 per month on her property valued at $160,000.

How much does Joe pay on his property valued at $323,000?

• $2,000

• $75.20

• $161.50

• $44.60