Question

Find the third proportional of4and12

Answer 1

Step-by-step explanation:

Given:-

numbers are 4 and 12

To find:-

Find the third proportional of 4 and 12

Solution:-

Given numbers are 4 and 12

Let the third proportional be X then

the proportion is

4:12::12:x

Product of extremes=4×X=4X

Product of means=12×12=144

We know that in a proportion product of means is equal to the product of extremes

=>4X=144

= X=144/4

=>X=36

Answer:-

The third proportional of 4 and 12 =36

Short cut:-

If a,b,c are in the proportion then the third proportional is c=b²/a

here a=4 and b=12

c=12²/4

=>c=144/4

=>c=36