A ratio is a comparison of two similar quantities obtained by dividing one quantity by the other. Ratios are written with the : symbol.
Example:The ratio of 6 to 3 is
6 ÷ 3 = 6/3 = 6 : 3 = 2
Example:The ratio of 3 to 6 is
3 ÷ 6 = 3/6 = 3 : 6 = 1/2
A proportion is a statement of the equality of two ratios.
Example:6 : 3 = 2 : 1 or 6 / 3 = 2 / 1or
62
- = -
31
are ways to write the proportion expressed as:6 is to 3 as 2 is to 1
Example:2 : 8 = 1 : 4 or 2 / 8 = 1 / 4or
21
- = -
84
are ways to write the proportion expressed as:2 is to 8 as 1 is to 4