Exercise 11 Page 148

To determine a percent change p, we can use the following general formula. p % =Amount of increase or decrease/Original amountFrom the given values, we can see the original amount was 40.2 and the new amount is 38.6, which is a decrease. 40.2-38.6= 1.6 The difference between the new amount and the original amount is 1.6. Now we can use the formula.

Percent change=Amount of decrease/Original amount

SubstituteValues

Substitute values

Percent change=1.6/40.2

ReduceFrac

a/b=.a /2./.b /2.

Percent change=0.8/20.1

UseCalc

Use a calculator

Percent change ≈ 0.04

WritePercent

Convert to percent

Percent change ≈ 4 %

The percent decrease is about 4 %.