## MathSofiya 2 years ago Intro to Statistics: $\mu=\sum xP(x)$ $\mu$ is the expected value of x So would I add the x values and P(x) values and then multiply them to get $\mu$? x: 0 1 2 3 4 5 P(x): 0.237 0.396 0.264 0.088 0.015 0.001

1. hartnn

multiply corresponding x and p(x) values, like 0*0.237+1*0.396 .......

2. slaaibak

you would multiply 0 by 0.237 add it to 1 times .396 add it to 2 times 0.264 etc... the sum would be u

3. MathSofiya

oh ok. It seemed too simple

4. MathSofiya

Thanks

5. hartnn

welcome ^_^

6. MathSofiya

for the standard deviation I have the equation $\sigma=\sqrt{\sum(x-\mu)^2P(x)}$ So, here I do: $0-\mu=-1.253$ $1-\mu=1-1.253=-.253$ $2-\mu=2-1.253=.747$ $3-\mu=3-1.253=1.747$ $4-\mu=4-1.253=2.747$ $5-\mu=5-1.253=3.747$ square each solution then multiply to P(x), then add those solutions up

7. hartnn

yes! finally take square root then.

8. MathSofiya

oh yes of course. Thank you!

9. MathSofiya

how do I make a table in latex? I have to submit my work electronically and a table would make it easier.

10. MathSofiya

I couldn't find it here http://en.wikipedia.org/wiki/Help:Displaying_a_formula#Diagrams_in_TeX

11. hartnn

let me search.

12. hartnn
13. hartnn

maybe write in matrix form .....of nX2 i'll look up something specifically for table

14. MathSofiya

oh ok, thanks

15. hartnn
16. MathSofiya

\hlines what does that do?

17. MathSofiya

I think I get it. I'll just use \\ \hlines before i move on to the next line. Makes sense

18. hartnn
19. MathSofiya

oh perfect! There's the explanations for \hlines. Thanks! =D