Proportional Relationships Practice Test Review

Proportional Relationships Practice Test Review

8th Grade Practice Test Review and More Problems to Solve

Find the Constant of Proportionality

Remember: a constant is a number

A blue whale travels 27.2 miles in 2 hours. What is the whale's average speed in miles per hour?

• Constant = y/x

• Constant = 27.2 / 2

• 13.6 miles per hour

Is there a proportional relationship between miles and dollars? 

• Find the constant (y/x) for each row and compare:

• Row 1: constant =22.40/5 = 4.48

• Row 2: constant = 59.20/15 = 3.9466

• Row 3: constant = 77.60/20 = 3.88

• No, there is not a proportional relationship because...

Multiple Choice

Is there a proportional relationship between the number of trees and the number of apples?

• Yes

• No

Open Ended

Explain, using numerical evidence, why the chart DOES represent a proportional relationship.

Write a Proportional Line

Use the format y=kx

Which mathematical statement below represents a proportional relationship?

• Proportional Relationships are written in the form y=kx

Multiple Choice

Is the equation proportional? y=3x

• Proportional

• NOT Proportional

Multiple Choice

Is the equation proportional? y=3x +7

• Proportional

• NOT Proportional

Multiple Choice

Is the equation proportional? y=0.5x

• Proportional

• NOT Proportional

Multiple Choice

Is the equation proportional? y=x/5

• Proportional

• NOT Proportional

Given a constant we can write an equation.

• If the constant is 4, the equation of the line is y=4x

• If the constant is 9, the equation of the line is y=9x

• If the constant is 0.3, the equation of the line is y=0.3x

A company donates $200 for every home run hit in a local Baseball game. Write an equation for the situation, where y is the total amount of money donated and x is the number of home runs hit. 

• The constant is 200.

• We use the form y=mx to represent a proportional equation

• y=200x

Type an equation to model the proportional relationship shown in the graph.

• y=mx

• Find the constant (unit rate) and substitute the value in for m. constant=y/x constant=38/2

• y=19x

Fill in the Blanks

The table shown represents a proportional relationship. What is the constant of proportionality? 

• Remember a constant is a number.

• Constant = y/x constant = 132/8 = 16.5

• Constant =y/x constant =148.5/9 = 16.5

• The constant is 16.5

Fill in the Blanks

Application

Which store charges more for a sheet of stickers?

• The equation y=2.09x models the cost y of x sheets of stickers at Sally's Stickers . So, the constant is 2.09

• The table shows the relationship between the cost and the number of sheets of stickers at Henry's Stickers. The constant is y/x, so the constant is 6.15/3, 2.05

• Sally's Stickers charges more.

• 
  

Multiple Choice

What store charges more for bananas? Price Chopper's prices are listed in the table, Hannaford's is represented by the equation y=2.5x

• Price Chopper

• Hannaford

Make sure to study for the test tomorrow!