Elementary Algebra

Let X represent the number of people expected to vote. Three out of every seven eligible voters are going to vote, so the ratio is $\frac{3}{7}$. Now, let’s set up a proportion with the ratio given and a ratio which compares the corresponding number of people. So, $\frac{3}{7}$ = $\frac{X}{210000}$ To solve this equation, we equate the cross products. 3 $\times$ 210000 = 7 $\times$ X 630000 = 7X X = 90000