Answer
$x = 45.5$
Work Step by Step
To solve a proportion, we use the cross products property, multiplying the numerator of one ratio with the denominator of the other ratio, and vice versa:
$3.5(5.2) = 0.4x$
Multiply on the left side of the equation:
$18.2 = 0.4x$
Divide each side of the equation by $0.4$ to solve for $x$:
$x = 45.5$
