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
<em><u>Solution:</u></em>
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.
<em><u>THE PERCENT CHANGE IS GIVEN AS:</u></em>
![\text{ percent change } =\frac{\text { final value - initial value }}{\text { initial value }} \times 100](https://tex.z-dn.net/?f=%5Ctext%7B%20percent%20change%20%7D%20%3D%5Cfrac%7B%5Ctext%20%7B%20final%20value%20-%20initial%20value%20%7D%7D%7B%5Ctext%20%7B%20initial%20value%20%7D%7D%20%5Ctimes%20100)
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 }=\frac{849-989}{989} \times 100\\\\&\text { percent change }=-0.14155 \times 100=-14.156 \%\end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D%26%5Ctext%20%7B%20percent%20change%20%7D%3D%5Cfrac%7B849-989%7D%7B989%7D%20%5Ctimes%20100%5C%5C%5C%5C%26%5Ctext%20%7B%20percent%20change%20%7D%3D-0.14155%20%5Ctimes%20100%3D-14.156%20%5C%25%5Cend%7Baligned%7D)
Here negative sign denotes percentage decrease
Thus percentage change is 14.156 % decrease