Proportions A proportion is an equation with a ratio on each side. It is a statement that two ratios are equal. 3 = 6 is an example of a proportion. 4 8 (A ratio is a fraction.)
How can you tell if ratios are in proportion?
Tell whether the ratios are proportional Since the cross products are equal, the ratios are proportional. 60 = ? 60 = 60 Find cross products
Tell whether the ratios are proportional. Since the cross products are equal, the ratios are proportional = 20 Find cross products = ?
Solving Proportions When you do not know one of the four numbers in a proportion, set the cross products equal to each other and solve.
Solve the Proportion 6p = 12 5 p = 10 6p = 60 Find the cross products. Solve p 12 = ; the proportion checks =
Solve the Proportion 14 3 = 2g 21 = g 42 = 2g Find the cross products. Solve g = ; the proportion checks =