Unit 6: Proportionality and percentages

What is the ratio between 3 and 6?

What is the ratio between 8 and 12?

• 82

• 12

• True, because there's a common number in each numerator and denominator.

Complete the following chart of direct proportionality and find the ratio of direct proportionality:

• k=0.2

  x=2.4

  y=10

• k=0.2

  x=2.5

  y=10

• k=0.4

  x=2.5

  y=10

• k=0.2

  x=2.4

  y=8

• k=0.4

  x=2.4

  y=8

Complete the following chart of inverse proportionality and find the ratio of inverse proportionality:

• k=48

  x=4

  y=6

• k=48

  x=3

  y=6

• k=48

  x=4

  y=8

• k=48

  x=3

  y=8

• k=40

  x=3

  y=8

What is the kind of proportionality between these magnitudes?

The distance a car travels and the amount of gasoline it uses.

• Direct proportionality

• Inverse proportionality

• There's no proportionality between them

What is the kind of proportionality between these magnitudes?

A person's weight and height.

• Direct proportionality

• Inverse proportionality

• There's no proportionality between them