Understanding Direct Proportions

What is a direct proportion?

• A direct proportion is a relationship where two quantities increase or decrease together at a constant rate.

• A direct proportion is when two quantities decrease together at a variable rate.

• A direct proportion is when one quantity remains constant while the other changes.

• A direct proportion is a relationship where two quantities are unrelated.

If y is directly proportional to x, and y = 12 when x = 3, what is the constant of proportionality?

• 6

• 8

• 2

• 4

Solve for x: 4/x = 2/8

• 4

• 16

• 8

• 2

Graph the proportional relationship between x and y if y = 5x. What does the graph look like?

• The graph is a horizontal line at y = 5.

• The graph is a straight line with a slope of 1.

• The graph is a straight line passing through the origin with a slope of 5.

• The graph is a curved line that does not pass through the origin.

Convert 3 meters to centimeters using proportions.

• 400 centimeters

• 150 centimeters

• 250 centimeters

• 300 centimeters

If 5 apples cost $2, how much do 15 apples cost?

• $4.00

• $8.00

• $10.00

• $6.00

Identify the direct proportion in the following: 2/3 = x/9.

• 6

• 4

• 12

• 3

If the ratio of boys to girls in a class is 3:4, how many girls are there if there are 12 boys?

• 14

• 18

• 20

• 16

If a car travels 60 miles in 1 hour, how far will it travel in 3 hours?

• 120 miles

• 240 miles

• 90 miles

• 180 miles

What is the constant of proportionality in the equation y = 7x?

• 10

• 5

• 3

• 7