# Proportion

In case of an analogy, two quantities share same kind of relationship.

For example, what Macbeth is to William Shakespeare, Dr Zivago is to Boris Pasternak.

In QA, the same is true for proportion. It is basically the equality of the two ratios.

When A, B, C and D are in proportion, then A and D are known as â€˜extremesâ€™ and B and C are known as â€˜meansâ€™.

Thus, we can say,
Product of Extremes = Product of Means

Example
What is the value of x in the following expression?
Solution
â‡’ x =

It can be calculated with the help of percentages also. In this question, the percentage increase in the denominator is 50%, so the numerator will also increase by 50%.