In details

Fundamental property of proportions


Note the following proportions:

Media Product = 4.30 = 120
Product of the extremes = 3.40 = 120

Media Product = 9.20 = 180
Product of the extremes = 4.45 = 180

Media Product = 8.45 = 360
Product of the extremes = 5.72 = 360

In general, we have to:

Hence we can state the fundamental property of proportions:

In every proportion the product of the media is equal to the product of the extremes. Next: Fundamental Property Applications