Geometric Distribution and probability

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Homework Statement



Assume that each of your calls to a popular radio station has a probability of 0.02 of connecting, that is, of not obtaining a busy signal. Assume that your calls are independent.

What is the probability that it requires more than five calls for you to connect?

Homework Equations



f(x) = (1 - p)^x-1*p


The Attempt at a Solution



P(X > 5) = 1 - P(X <= 5)
= 1 - [P(X=1) + P(X=2) + P(X=3) +P(X=4)+P(X=5)]
= 1 - [.98^0(.02)+.98^1(.02)+.98^2(.02)+.98^3(.02)+.98^4(.02)]
= 1 - [(.02)(.98^0 + .98^1 + .98^2 + .98^3 + .98^4)]
= 0.9239
 
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Well it seems ok, assuming you computed the values correctly.
 
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