02 Ratio Proportion and Variation
5. Proportions
5.2. Third Proportional
If \(x\) is the third proportional of the numbers \(a\) and \(b\), then \(a : b :: b : x\) \( \Rightarrow \frac{a}{b} = \frac{b}{x}\) or \(x\) = \(\frac{{{b^2}}}{a}\)
If \(x\) is the third proportional of the numbers \(a\) and \(b\), then \(a : b :: b : x\) \( \Rightarrow \frac{a}{b} = \frac{b}{x}\) or \(x\) = \(\frac{{{b^2}}}{a}\)