Help me find mean and variance in a probability task

[johnchau123]

Question: Consider a six-sided die is rolled n independent times and the outcome of the experiment is the mean of this n trials. Find the mean and variance.

Actually, to the question, I am not sure what is meant by "utcome of the experiment is the mean of this n trials". Can anyone tell me what this key sentence means?

Thanks

 

[neils_arm_strong]

Mean and variance

Outcome of an experiment is random,then the output of conducting it several times will be a random variable whose mean can be calculated.But if a die is rolled n times each time then the mean of this will be constant and mean of all such costant o/ps is that costant itself and ofcource the variance is zero since the outcome each time is const.

 

[vestan]

Re: Mean and variance

You have 6 equal-probability results.

Every result is Xi i=1,...,n

MEAN <xi>=(1/n)∑Xi =x; The sum is in i;

VARIANCE σ^2=<(Xi -<Xi>)^2>=(1/n)∑((Xi-x)^2); the sum is in i