SOLUTION: what is the probability of 4 calculator batteries with a 90% chance of lasting one year?

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Question 395744: what is the probability of 4 calculator batteries with a 90% chance of lasting one year?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

Note: The probability of x successes in n trials is: 

P = nCx* p%5Ex%2Aq%5E%28n-x%29 where p and q are the probabilities of success and failure respectively. 

In this case p = .9 and q = .1 

nCx = n%21%2F%28x%21%28n-x%21%29%29

P(4 out of 4 lasting one year) = (.9)^4 = .6561