What is the ratio of the third proportional of 0.4 and 0.8 to the mean proportional of 13.5 and 0.24?
Answer & explanation
Correct answer: option 3
Third proportional of a & b = \(\frac{b^2}{a}\)
Hence third proportional of .4 & .8 = \(\frac{(.8)^2}{.4}\) = 1.6
Mean proportional of a & b = \(\sqrt {ab}\)
Hence Mean proportional of 13.5 & .24 = \(\sqrt {13.5 × .24}\) = \(\sqrt {3.24}\) = 1.8
Required ratio ⇒ 1.6 : 1.8 ⇒ 8 : 9