Ratios and Proportions
A ratio is a way to compare two quantities using division.
Ratios are often written as fractions.
â€¢ If a class of 24 students contains 11 women and 13 men, then the ratio of women to men is 11 to 13, which we can write as .
â€¢ If 10 pounds of watermelon costs $3, then the ratio of cost to weight is .A proportion is an equation that sets one ratio equal to another ratio.
Definition â€” Proportion
A proportion is an equation that can be written in the form
Here b ≠ 0 and d ≠ 0.Hereâ€™s a problem we can solve with a proportion.
If an 18-pound melon costs $3.60, what is the cost of a 26-pound melon?
The cost of the big melon is $5.20.