Question

Find the fourth proportional to 12, 30, 18.​

Answer 1

Answer:

Step-by-step explanation:

12:18::20:x

product of means product of extremes

18 × 20 = 12 x x

360 =12x

12 x = 360

x = 360/12

x = 30

Answer 2

Step-by-step explanation:

Let the fourth proportionate be x then

12, 30, 18, x can be written as

12:30:: 18: x

12/30::80/x

x=80*30/12

x= 80*5/2

x=40*5

x=200