- #1
cookiesyum
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Homework Statement
Let X have a geometric distribution. Show that
P(x>or= k+j|x>or=k) = P(X>or=j)
where k and j are nonnegative integers.
The Attempt at a Solution
P(x>or= k+j|x>or=k) = P(x>or= k+j intersect x>or=k)/P(x>or=k) = P(x>or=k+j)/P(x>or=k) for j>or= 0 = [1-P(x=k+j)]/[1-P(x=k)] = [1 - p(1-p)^(k+j)]/[1-p(1-p)^k] = [1-p(1-p)^k(1-p)^j]/[1-p(1-p)^k] = (1-p)^j which is equal to P(x>or=j) if it had another p so that it was p(1-p)^j...so where am I losing this p in my proof?