## MathSofiya Group Title 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 one year ago one year ago

1. hartnn Group Title

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

2. slaaibak Group Title

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 Group Title

oh ok. It seemed too simple

4. MathSofiya Group Title

Thanks

5. hartnn Group Title

welcome ^_^

6. MathSofiya Group Title

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 Group Title

yes! finally take square root then.

8. MathSofiya Group Title

oh yes of course. Thank you!

9. MathSofiya Group Title

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

10. MathSofiya Group Title

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

11. hartnn Group Title

let me search.

12. hartnn Group Title
13. hartnn Group Title

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

14. MathSofiya Group Title

oh ok, thanks

15. hartnn Group Title
16. MathSofiya Group Title

\hlines what does that do?

17. MathSofiya Group Title

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

18. hartnn Group Title
19. MathSofiya Group Title

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