Ratios and Proportions

Ratio: A comparison of 2 numbers. 4 Apples to 5 Oranges, 3 Boys to every 1 Girl,
2 Hotdogs per Hamburger
Ratios are written 3 ways: As a Fraction, With : (a colon), and Using the word "to"

Proportion

A proportion is a statement that 2 ratios are equal, or balanced.

Example

Another Example

X = 30
We find this by multiplying 6 and 10 = 60 then dividing by 2.

Solving

Many times, we are asked to SOLVE a Proportion. In order to solve, you set up the proportion, using a variable for the unknown amount. Then cross multiply and divide. You can also find the relationship between the first fraction and the second. Use that to solve for the unknown amount.