Question : Calculate E[X] and Var[X] when X represents the outcome when a fair die is rolled.

---------------------------------------------------------------------

Printable View

- December 30th 2009, 01:09 AMzorroCalculate E[X] and Var[X]
Question : Calculate E[X] and Var[X] when X represents the outcome when a fair die is rolled.

---------------------------------------------------------------------

- December 30th 2009, 01:24 AMmr fantastic
- December 30th 2009, 10:15 PMzorro
I am getting the following results

E[X] =

Var[X] = 3.07 .................Is that correct??? - December 30th 2009, 10:35 PMmatheagle
E(x)=3.5

- December 31st 2009, 08:31 AMpencil09
- December 31st 2009, 09:14 PMmr fantastic
I think you know now that the first is not correct (I haven't checked the second).

When I say:

Quote:

Please show all your work if you're still stuck.

**all**the work. If you had done this, it (probably) would have been simple to point out the mistake you made. Post #5 shows what I expected you to post when I said:

Quote:

Substitute f(x) and the values of x into the formulas that you have quoted and do the calculations

- January 1st 2010, 03:47 AMzorro
thanks mite

cheers