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You are raising money for your club by calling old club members. You are asking for a $10 donation from each member. Each call is independent and has a probability of success of receiving $10 on any one call is 60%. You need to raise $100 and you stop when you’ve achieved that goal. What is the probability that you take exactly 15 calls to reach your goal.

 Mar 24, 2020
 #1
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This  is a binomial probability problem

 

Assuming that  we are succeful on the 15th call, we need any 9 of the first 14  to be successful...so we have

 

C(14,9)(.60)^9 (.40)^5 * (.60)   ≈ .2066 ≈  20.66%

 

 

cool cool cool

 Mar 24, 2020

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