|Class 6 Maths Ratio And Proportion||Proportion|
If two ratios are equal, we say that they are in proportion and use the
Symbol ‘::’ or ‘=’ to equate the two ratios. Four quantities are said to be in proportion, if the ratio of the first and the second quantities is equal to the ratio of the third and the fourth quantities.
For e.g., we can say 2, 10, 5 and 25 are in proportion which is written as
2 : 10 :: 5 : 25 and is read as 2 is to 10 as 5 is to 25 or it is written as 2 : 10 = 5 : 25.
If two ratios are not equal, then we say that they are not in proportion.
In a statement of proportion, the four quantities involved when taken in order are known as respective terms. First and fourth terms are known as extreme terms. Second and third terms are known as middle terms. In the above example, 2 and 25 are extreme terms while 10 and 5 are middle terms.