Question

Find the fourth proportional of 5,8,12​

Answer 1

Solution :

Let, the fourth proportional be x

5 : 8 :: 12 : x

⇒ 5/8 = 12/x

⇒ 5x = 12 × 8

⇒ 5x = 96

⇒ x = 96/5

⇒ x = 19.2

★ Fourth proportional is 19.2

Answer 2

Given :-

We have to find the fourth proportional to 5,8,12.

Solution :-

Let the number be x.

5 : 8 :: 12 : x

We can write it as,

➳ 5/8 = 12/x.

➳ 5x = 8 × 12.

➳ 5x = 96.

➳ x = 96/5.

➳ x = 19.2

Hence,Fourth Proportional was 19.2.