Question

Find the fourth proportional to 5,7 and 25

Answer 1

Step-by-step explanation:

let the fourth proportional be x

5:7 = 25:x

5/7 = 25/x

5x = 25×7 [ upon cross multiplication ]

therefore x = (25×7)/5 => 35

Answer 2

The fourth propotional to 5, 7, 25 is 35.

To find :-

The fourth propotional to 5,7 and 25.

Solution :-

Let the fourth propotional to 5, 7, 25 be x.

Then,  5, 7, 25 and x are in proportional.

i.e.

$\frac{5}{7}=\frac{25}{x}$

Let's solve it.

$\frac{5}{7}=\frac{25}{x} \\ \\ => x \times 5 =25 \times 7\\ \\ (By\: \:cross\:-\:multiplication)\\ \\ =>x=\frac{25 \times 7}{5} \\ \\=>x=\frac{175}{5} \\ \\=>x=35$

Answer :-

Therefore, the fourth proportional to 5, 7, 25 is 35.