Question

If 4, x, 9 are in continued proportion, find the value x.

Answer 1

It is given that 4, x, 9 are in continued proportion; therefore, we have:

4 : x : : x : 9

$$\begin{gathered} \Rightarrow \frac{4}{x}=\frac{x}{9}=4\times 9=x^2 \\ \Rightarrow x^2=36\Rightarrow x=6 \end{gathered}$$