Proportional Relationships Intro

Does the table represent a proportional relationship?

• yes

• no

The graph shows the cost C in dollars of w pounds of blueberries, a proportional relationship. Select all the true statements.

• 1 pound of blueberries costs $2.75

• 2.75 pounds of blueberries cost $1

• 5 pounds of blueberries cost $15.50

• 12 pounds of blueberries cost $33

• The point (3,9) is on the graph of the proportional relationship

Answer explanation

Find the unit rate (cost of one pound) and/or use a table. TWO statements are correct.

The table shows the weights of apples at a grocery store. Complete the RED box (weight of 2 apples) so that there is a proportional relationship between the number of apples and their weight.

Give the NUMBER ONLY, no units.

Answer explanation

To start, find the weight of ONE apple. This is your unit rate; it is also your constant of proportionality.

The table shows the weights of apples at a grocery store. Complete the BLUE box (weight of 12 apples) so that there is a proportional relationship between the number of apples and their weight.

Give the NUMBER ONLY, no units.

Answer explanation

To start, find the weight of ONE apple. This is your unit rate; it is also your constant of proportionality.

A recipe for salad dressing calls for 3 tablespoons of oil for every 2 tablespoons of vinegar. The line represents the relationship between the amount of oil and the amount of vinegar needed to make salad dressing according to this recipe. The point (1, 1.5) is on the line. Label the vertical axis (BLUE box).

• Oil (tablespoons)

• Vinegar (tablespoons)

If there is a positive constant k so that the quantities x and y are related by the equation y=kx, then we say that y and x are in a _____ relationship.

• complicated

• equivalent

• proportional

• scale

In the equation y=kx, the term k is called the...

• equivalent ratio

• constant of proportionality

• cult of personality

• scale drawing

Which graph represents a proportional relationship?

• 
• 
• 
• 

Answer explanation

The graph should be a straight line through the origin (0,0).

The two lines represent the amount of water, over time, in two tanks that are the same size. Which container is filling more quickly?

• Container A is filling more quickly

• Container B is filling more quickly

Explain how you know which container is filling more quickly.

Answer explanation

The container that is filling more quickly is the one for which the graph is steeper.