[h=2]Notation and terminology[/h] The ratio of numbers
A and
B can be expressed as:
[4]
- the ratio of A to B
- A is to B (followed by "as C is to D")
- A:B
- A fraction that is the quotient of A divided by B:
The numbers
A and
B are sometimes called
terms with
A being the
antecedent and
B being the
consequent.
[citation needed]
The proportion expressing the equality of the ratios
A:
B and
C:
D is written
A:
B =
C:
D or
A:
B::
C:
D. This latter form, when spoken or written in the English language, is often expressed as
A is to B as C is to D.
A,
B,
C and
D are called the terms of the proportion.
A and
D are called the
extremes, and
B and
C are called the
means. The equality of three or more proportions is called a continued proportion.
[5]
Ratios are sometimes used with three or more terms. The ratio of the dimensions of a "
two by four" that is ten inches long is 2:4:10. A good concrete mix is sometimes quoted as 1:2:4 for the ratio of cement to sand to gravel.
[6]
For a mixture of 4/1 cement to water, it could be said that the ratio of cement to water is 4:1, that there is 4 times as much cement as water, or that there is a quarter (1/4) as much water as cement..
Older
televisions have a 4:3
aspect ratio, which means that the width is 4/3 of the height; modern widescreen TVs have a 16:9 aspect ratio.