- #1
Kisa30
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Homework Statement
let x be a random variable with
P(X=-1) = 1/4
P(X=0) = 1/4
P(X=1) = 1/2
Let S be the sum of 25 independant random variables each with the same distribution as X.
Calculate approximately
a) P(S<0)
b) P(S=0)
c) P(S>0)
Homework Equations
Quite possibly the normal approximation.
The Attempt at a Solution
I'm not sure how to start this at all. Please help.
The answers are
a) P(S<0) = 0.05
b) P(S=0) = 0.03
c) P(S>0) = 0.92
Thanks in advanced!