• Welcome! The new FreeMathHelp.com forum is live. We've moved from VB4 to Xenforo 2.1 as our underlying software. Hopefully you find the upgrade to be a positive change. Please feel free to reach out as issues arise -- things will be a little different, and minor issues will no doubt crop up.

sample mean and variance

Jeonsah

New member
Joined
Feb 5, 2012
Messages
14
Hey guys, I am lost on how to calculate the sample mean/variance for this problem:

Plot the probability mass function of the sample mean of X1, ...,Xn, when
a) n = 2;
a) n = 3.

Assume that the probability mass function of the sample mean of X1,...,Xn is
P{X = 0} = .2, P{X = 1} = .3, P{X = 3} = .5


The answer in the back of the book is
E[sample mean] = 1.8
V[Sample mean] = 4.8/n

Any help is appreciated.
 

tkhunny

Moderator
Staff member
Joined
Apr 12, 2005
Messages
9,708
You must resort to the definition of the mean. Let's see what you get.
 
Top