Question

answer this proportion question.

Answer 1

let the third proportional be x,

therefore,12:30:x

or 12:30=30:x

or 12×x =30×30

or x = 900÷12

or x =75

let the mean proportional be x

therefore,9:x:25

or 9:x = x:25

or 9×25 x×x

or 225 = x²

or √225 = x

or 15 = x

Answer 2

mean proportion of 9,25 is x=root(ab)
x=root(9×25)
x=root225
x=15
third proportional of 12,30 is
x=b^2/a
x=(30)^2/12
x=900/12
x=75
ratio of third to mean proportional is
75/15
=5/1
5:1 is ratio
so option b is answer obtained