Exercise 71 Page 170

To determine percent change p, we can use the following general formula. p %=Amount increase or decrease/Original amountFrom the given values, we can see the original amount was 36 and the new amount is 12. This is a decrease in the amount. 36- 12= 24 The difference between the original amount and the new amount is 24. Now, we can use the formula.

Percent change=Amount of decrease/Original amount

SubstituteValues

Substitute values

Percent change=24/36

ReduceFrac

a/b=.a /12./.b /12.

Percent change=2/3

UseCalc

Use a calculator

Percent change=0.666666...

RoundDec

Round to 2 decimal place(s)

Percent change≈ 0.67

WritePercent

Convert to percent

Percent change ≈ 67 %

The percent decrease is about 67 %.