Question

If9,x,x,49 are in proportion, find the valve of

Answer 1

ANSWER WITH FULL EXPLANATION

In the question, it is given that $9$, $x$, $x$ and $49$ are in continued proportion. So, we can write it as
$9:x::x:49$
⇒ $x*x=9*49$          [∵ Product of means = Product of extremes]
⇒ $x^{2}=441$
⇒ $\sqrt{x^{2}}=\sqrt{441}$
⇒ $x=21$

∴ $x=21$

Hope this may help you. 

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