To solve this proportion, we must use the percent proportion equation,
a/b=p/100
If we put in our known variables, we get the equation
a/13000=22/100
Net, we use cross products to simplify this equation, or multiplying the numerator of one fraction by the denominator of another fraction and setting them equal to one another.
100a=286000
Finally, we divide both sides by the coefficient of the variable, to get it alone:
a = 2860
Therefore, 2860 people out of the total 13000 people that live in Centerville are under the age of 18.
