Exploring Proportional Relationships

Which of the following represents a proportional relationship?

• The cost of apples is $3 per pound.

• The temperature increases by 5 degrees every hour.

• The number of students in a class is 25.

• The height of a plant increases by 2 cm every week.

• 6

• 8

• 9

• 10

If a car travels 180 miles in 3 hours, what is the unit rate in miles per hour?

• 30 miles per hour

• 50 miles per hour

• 60 miles per hour

• 90 miles per hour

• 1

• 7

• 0

• 14

If 5 notebooks cost $15, what is the cost of 8 notebooks?

• $20

• $24

• $30

• $36

Which of the following is NOT a proportional relationship?

• The number of pages read is proportional to the time spent reading.

• The distance traveled is proportional to the speed.

• The area of a square is proportional to the length of its side.

• The number of cookies is proportional to the number of batches baked.

If a recipe requires 3 cups of flour for every 2 cups of sugar, what is the ratio of flour to sugar?

• 2:3

• 3:2

• 1:2

• 2:1