What is the product of means and extremes?

The product of means and extremes refers to a property in proportions. If two ratiOS (a/b = c/d) are equal, then the product of the means (b and c) is equal to the product of the extremes (a and d), expressed as (b \cdot c = a \cdot d). This relationship is often used in solving problems involving proportions, ensuring that the cross-multiplication yields equivalent results.