Exercise 27 Page 149

To determine the percent change p, we can use the following general formula. p % =Amount of increase or decrease/Original amountFrom the given weights, we can see that the original weight is greater than the new weight. To find the decrease, we have to subtract the new amount from the original one. 140 14 - 80 34 = 59 12 Knowing how much the weight decreased, we can now use the formula to calculate the percent decrease.

Percent change=Amount of decrease/Original amount

SubstituteValues

Substitute values

Percent change=59 12/140 14

WriteDec

Write as a decimal

Percent change=59.5/140.25

UseCalc

Use a calculator

Percent change=0.424242...

RoundDec

Round to 2 decimal place(s)

Percent change≈ 0.42

WritePercent

Convert to percent

Percent change≈ 42 %

The percent change is approximately 42 %.