What is the ratio of the third proportional of 5 & 9 and the mean proportional between 1.6 and 8.1?
Answer & explanation
Correct answer: option 3
Third proportional a, b, c
c = \(\frac{b2}{a}\)
third proportional = 5, 9, x
x = \(\frac{81}{5}\)
Mean proportional = \(\sqrt {1.6 × 8.1}\)
= 3.6
3rd proportional : mean proportional
\(\frac{81}{5}\) : 3.6
9 : 2