Business Mathematics Brief 12th Edition by Stanley Salzman ,Gary Clendenen, Charles Miller

تمرين 109

Explain the difference between ratio and proportion. (See Objective.)
Set up a proportion. A ratio is used to compare two numbers or amounts. A proportion says that two ratios are equal, as shown here.

A proportion can be simplified by multiplying both sides of the equation by the product of the two denominators.

Thus,
only if the cross products a • d and b • c are equal to one another. This method of cross products can be used to determine if a proportion is true.