## anonymous 4 years ago The random variable, X, has the probability density function $f(x)=\left(\begin{matrix}kx^3 \\ 0\end{matrix}\right)$$0\le x \le 2 - {otherwise} -$ Find the probability that an observation lies withing one standard deviation of the mean.

1. anonymous

k=1/4 btw

2. anonymous

can we use Chernoff's inequality?

3. anonymous

What's that?... I don't know it by name..

4. anonymous
5. cristiann

Probability 0.7

6. anonymous

Let me just read it through and see if I understand everything, but it's the right answer.

7. anonymous

One question, what does M stand for?

8. anonymous

mean?

9. cristiann

Yes ... mean ... average ...

10. anonymous

Then I understand it. Thank you!

11. cristiann

E(X) in fact ... I've used another notation ...sorry...

12. cristiann

You are welcome ... :)

13. anonymous

That's fine. I know it as $\mu$ aswell

14. amistre64

f(x)={{kx^3}\choose{0}} might be an easier way to type that up $f(x)={ {kx^3}\choose{0}}$