Exercise 21 Page 415

To determine 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 $2000 and the new amount is $2100. This is an increase in the amount. 2100-2000= 100 The difference between the new amount and the original amount is $100. Now we can use the formula.

Percent change=Amount of increase/Original amount

SubstituteValues

Substitute values

Percent change=100/2000

ReduceFrac

a/b=.a /100./.b /100.

Percent change=1/20

UseCalc

Use a calculator

Percent change=0.05

WritePercent

Convert to percent

Percent change = 5 %

The percent increase is 5 %.