Ratio
A ratio shows the relationship between two quantities. You write it often with a colon as
a : b
and you call it the quotient of a and b.
Explanation
In general you can write
Numerator = Dividend = Quotient = Fraction = Ratio Denominator Divisor
Example 1
Ratios can be calculated by cross-multiplication
a : b = c : d
gives then
a × d = b × c
Example 2
Two quantities are in the golden ratio if their ratio is the same as the ratio of their sum to the larger of the two quantities
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where a > b > 0.
Example 3
The number π = 3.1415… describes the ratio between the circumference and the diameter of a circle
π = circumference diameter
and cannot be written by any pair of whole numbers. It is an irrational number.
Example 4
The number √2 = 1,4142... is the ratio between the side and the diameter of a square, and cannot be written by any pair of whole numbers. It is an irrational number.
Example 5
A probability is the ratio between the number of favorable outcomes and the number of possible outcomes
P(G) = number of favorable outcomes number of possible outcomes