Given:
12% decrease followed by a 18% increase.
To find:
The single percentage change is equivalent to the given set of percentages.
Solution:
Let the initial value be 100.
After 12% decrease, the value is:
![v_1=100-(12)/(100)* 100](https://img.qammunity.org/2022/formulas/mathematics/high-school/10sh4mnqdp6o7hqlrvykgd04izjqvexqzu.png)
![v_1=100-12](https://img.qammunity.org/2022/formulas/mathematics/high-school/kydqlpa1may1e2xyko2p8wk20mi2qco23f.png)
![v_1=88](https://img.qammunity.org/2022/formulas/mathematics/high-school/927fnyikd3hch58dse10wig8ll38am9psi.png)
After 18% increase, the value is:
![v_2=88+(18)/(100)* 88](https://img.qammunity.org/2022/formulas/mathematics/high-school/kbzd4itcse8k9cab2yifg6rcp9vqbrmavw.png)
![v_2=88+15.84](https://img.qammunity.org/2022/formulas/mathematics/high-school/axcyq8loxxajrfpqvqexvayye1t31p0rwc.png)
![v_2=103.84](https://img.qammunity.org/2022/formulas/mathematics/high-school/yksss09a804ydjqa7vv4pgoih0wcvml8ks.png)
The initial value is 100 and the new value in 103.84. So, it represents increase in the value. So, increase percentage is
![Increase\%=\frac{\text{New -Initial}}{\text{Initial}}* 100](https://img.qammunity.org/2022/formulas/mathematics/high-school/suprp984rahab2f5v7aehseewxv7i6dynw.png)
![Increase\%=(103.84-100)/(100)* 100](https://img.qammunity.org/2022/formulas/mathematics/high-school/8drqn3x3g28pkn5nl2dtuw8hgb6ng8e6pw.png)
![Increase\%=3.84](https://img.qammunity.org/2022/formulas/mathematics/high-school/oa9ed3rxd4t01bz8x2ceo5uwg0niah2pqt.png)
Therefore, the value increased by 3.84%.