With cross multiplying, you take the numerator of the first ratio and multiply it by the denominator of the second ratio. Then, you set that equal to the denominator of the first ratio times the numerator of the second ration. Using the above proportion as an example, we can solve for x by cross multiplying.

Why do you cross multiply ratios?

Cross multiply fractions when you want to determine if one fraction is greater than another, or if you are looking for a missing numerator or denominator in equivalent fractions.

What is cross product in ratio?

A cross product is the result of multiplying the numerator of one ratio with the denominator of another. If the cross products are equal, then the ratios are proportional.