# cumulative distribution

• December 3rd 2009, 10:46 AM
babbagandu
cumulative distribution
Question attached as an image. It is # 6. Any help would be awesome, thanks
• December 3rd 2009, 01:39 PM
Focus
Could you please post an attempt? I don't mean to be rude but you are just posting a load of questions, for which it seems you shown no effort to do.

Here if a tip to get you started $\mathbb{P}(f(X)\leq a)=\mathbb{P}(X\leq f^{-1}(a))$.
• December 5th 2009, 09:51 AM
babbagandu
Thank you for the tip, but I am still a little confused. Could I have another hint maybe?
• December 6th 2009, 02:46 PM
Focus
Quote:

Originally Posted by babbagandu
Thank you for the tip, but I am still a little confused. Could I have another hint maybe?

Use this;

Quote:

Originally Posted by Focus
$\mathbb{P}(f(X)\leq a)=\mathbb{P}(X\leq f^{-1}(a))$.

in conjunction with the fact that $e^{\log X}=X$. When you have, you know what distribution X has, so you can explicitly write out the value.

If you want the hint more explicitly: $\log X \leq a$ take exponential of both sides.