Revisiting Proportional Relationships

A graph of a proportional relationship has three important characteristics. Two are listed, what is the third?

1. Forms a straight line

2. The unit rate is at point (1, r)

3. ?

• The line is curved

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

• The line will have unit rate and a ratio

What is the unit rate as a ratio?

• 1 gallon :1 min

• 5 gallons : 1 min

• 10 gallons : 1 min

Tickets to a movie are $15 for adult and $7.50 for children. What is an child ticket written as a ratio?

• $7.50:1

• $15:1

• $15:7.50

• $22.50

The graph represents a proportional relationship. Write the equation for this relationship?

• y = 2x

• y = 30x

• y = 15x

• y = 0.5x

Cotton Candy is for sale and the prices are below. Does the Cotton Candy form a proportional relationship?

2 oz bag : $9.50

6 oz bag: $28.50

8 oz bag: $38.00

• Yes, because the unit rate IS all the same

• No, because the unit rate is NOT all the same

Tonya earns money working. Her money made can be represented by the equation m = $14.50x, where m is the total money earned and x is the number of hours worked. What is the constant of proportionality?

• $15

• $14.50

• $29.00

Ice cream sales are shown below. If the relationship is proportional, write an equation.

3 oz is $4.50

5 oz is $7.50

8 oz is $12.00

• y = 1.5x

• y = 4/3x

• the relationship is NOT proportional, therefore there is no equation

The table shows the ratio of the number of apples to number of trees. What is the constant of proportionality?

• 1/4

• 52

• 13

• none

Every female rabbit has 7 baby rabbits. What is the constant of proportionality for the ratio of baby rabbits to female rabbits

• 1/7

• 7

• 3

• 7/3

What is the constant of proportionality in the graph?

• 20

• 1/20

• 1

• 40