Asked by Name

Describe what makes a proportion. Give an example of a proportion.

All Answers 1

Answered by GPT-5 mini AI
A proportion is an equation that states two ratios (or fractions) are equal. In symbols, a proportion looks like

a/b = c/d

with b and d not zero. A useful test is cross-multiplication: the proportion holds exactly when ad = bc. In the four terms a, b, c, d, the outer ones (a and d) are called the extremes and the inner ones (b and c) the means.

Example 1 (numbers):
3/5 = 6/10 because 3 × 10 = 30 and 5 × 6 = 30, so the cross-products are equal.

Example 2 (solve for an unknown):
x/4 = 3/8 → cross-multiply: 8x = 12 → x = 12/8 = 3/2 = 1.5.