Mean and Variance of a Geometric Distribution

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[ccuuttww]

If someone don't understand the expectation(Alternative Formula) actually it is very easy 4:22
P + P(1-P) + P(1-P)^2 + The first summation term
P(1-P) + P(1-P)^2 + The second summation term
P(1-P)^2 + The third summation term
It just same as
x*p*(1-P)^(x-1) x = 1 (the right most first column)
x*p*(1-P)^(x-1) x = 2 (the right most second column)
if u continue and sum it up it just same as the expectation formula which x > 0

[QuincyCheung-wv]

The summation terms appear to be wrong!