Question

PROPORTION..
find the fourth proportional of this sum
(I) 2.1, 1.5& 8.4 ​

Answer 1

Answer: The fourth proportional is 6.

Step-by-step explanation:

let the fourth proportional be x

2.1 : 1.5 :: 8.4 : x

when a:b ::c :d are in proportion  a * d = b*c

therefore 2.1 * x = 1.5 * 8.4

                 x = (1.5 * 8.4) / 2.1

                 x = 6