Let's start by recalling that a percent of change is a ratio that compares the change in quantity to the original amount. If the original quantity is increased, then it is called a percent of increase. If the original quantity is decreased, then it is called a percent of decrease. To determine the percent of change, we can use the following formula.

Percent of change = \frac{Amount of change}{Original amount}

In this case, the original quantity is

30

inches,

and the new quantity is

24

inches .

We can find the amount of change by subtracting the less value from the greater one.

Amount of change = 30 in . - 24 in . = 6 in .

Now let's use the formula to find the percent of change. To make the math easier, we can ignore the units for now.

Percent of change = \frac{Amount of change}{Original amount}

SubstituteII

$Amount of change = 6$ , $Original amount = 30$

Percent of change = \frac{6}{3 0}

UseCalc

Use a calculator

Percent of change = 0.2

To write the decimal as a percent, we need to move the decimal point two places to the right and write the percent symbol.

Percent of change = 0.2

WritePercent

Convert to percent

Percent of change = 20 %

We found that the percent of change is

20 % .

Finally, let's state whether the percent of change is an increase or a decrease. To do so, we need to compare the original quantity with the new quantity.

Original quantity 30 in . > New quantity 24 in .

Since the new quantity is less than the original quantity, this is a percent of decrease.

Exercise