Question

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

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

Step-by-step explanation:

third proportional of 12 and 30 is

12:30::30:x

x=30×30/12

x=75

mean proportional of 9 and 25 is

9:x::x:25

x×x=9×25

x×x=225

x=318.198