Exercise 67 Page 459

To determine percent change p, we can use the following general formula. p % =Increase or decrease in height/Original heightFrom the given values, we can see the original height was 15cm and the new height is 18cm. This is an increase in height. 18cm-15cm= 3cm The difference between the new height and the original height is 3cm. Now we can use the formula.

Percent change=Increase in height/Original height

SubstituteValues

Substitute values

Percent change=3/15

FracToDiv

a/b=a÷ b

Percent change= 0.2

WritePercent

Convert to percent

Percent change = 20 %