Question

Find the ratio of third proportional to 12 and 30 and the mean proportional between 9 and 25

Answer 1

Answer:

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