Ratio, proportion and rates of changeGCSE Higher

Proportional change without finding the constant

Compare scale factors without calculating the constant.

  • For , multiplying by multiplies by .
  • For , the multiplier is .

Example 1

is directly proportional to . The value of is multiplied by . By what factor is multiplied?

Apply the power, then take the reciprocal for inverse proportion.

Example 2

is inversely proportional to . The value of is multiplied by . By what factor is multiplied?

Apply the power, then take the reciprocal for inverse proportion.

Your turn

Question 1

is directly proportional to . The value of is multiplied by . By what factor is multiplied?

Check answer
Apply the power, then take the reciprocal for inverse proportion.
Question 2

is inversely proportional to . The value of is multiplied by . By what factor is multiplied?

Check answer
Apply the power, then take the reciprocal for inverse proportion.
Question 3

is directly proportional to . The value of is multiplied by . By what factor is multiplied?

Check answer
Apply the power, then take the reciprocal for inverse proportion.
Question 4

is inversely proportional to . The value of is multiplied by . By what factor is multiplied?

Check answer
Apply the power, then take the reciprocal for inverse proportion.
Question 5

is directly proportional to . The value of is multiplied by . By what factor is multiplied?

Check answer
Apply the power, then take the reciprocal for inverse proportion.
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