# Multiple Random Variables

• August 1st 2010, 11:09 AM
Hitman6267
Multiple Random Variables
Attachment 18400http://www.mathhelpforum.com/math-he...0&d=1280689693

can some one tell me what I need to do ? I'm lost.

I don't see what relationship I need to use to calculate their average.
• August 1st 2010, 10:25 PM
gustavodecastro
a) Try to use the CLT. You have to calculate $P(|\bar{X} - mu| \geq 6)$ using the change of variable $Z = (\bar{X} - \mu)/\var{\bar{X}}$

b) Since all the variables are independent,
$E(e^{t\sum_{k=1}^{36} X_k}) = E(e^{tX_1}) \dots E(e^{tX_{36}}) = \left(E(e^{tX_1})\right)^{36}$
and since you the distribution of X, you know the mgf.