Question

find x if 25 , 35 , x are in continued proportion

Answer 1

It's sequence so 25,35,45 .....so x=45

Answer 2

ANSWER WITH FULL EXPLANATION

In the question, it is given that $25$, $35$ and $x$ are in continued proportion. So, we can write it as
$25:35::35:x$
⇒ $25*x=35*35$             [∵ Product of means = Product of extremes]
⇒ $x = \frac{35*35}{25} = 49$

∴ $x=49$

Hope this may help you. 

If you have any doubt, then you can ask me in the comments.