Barry found a computer at Staples for $989. A week later, the computer went on sale for $849. The percentage change is 14.156 % decrease
Solution:
Given that Barry found a computer at Staples for $989
A week later, the computer went on sale for $849
To find: percent of change
Percent change is the extent to which a variable gains or loses value. The figures are arrived at by comparing the initial (or before) and final (or after) quantities according to a specific formula.
THE PERCENT CHANGE IS GIVEN AS:
![\text{ percent change } =\frac{\text { final value - initial value }}{\text { initial value }} * 100](https://img.qammunity.org/2020/formulas/mathematics/middle-school/in2x9wil4jdjsnlsf6h5ryw3zokn667x45.png)
If the result is positive, it is percentage increase
If the result is negative, it is percentage decrease
Here initial value = 989 and final value = 849
Substituting the values in above formula,
![\begin{aligned}&\text { percent change }=(849-989)/(989) * 100\\\\&\text { percent change }=-0.14155 * 100=-14.156 \%\end{aligned}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ntxv59zneij3t4huyq9rp46j0qmt4v3vud.png)
Here negative sign denotes percentage decrease
Thus percentage change is 14.156 % decrease