SOLUTION: Can Iget some help with this problem please.I tried some of it but get stuck. Thanks Kim The recovery rate from the flu is 0.9. If 4 people get the flu waht is the probabilty that

Algebra ->  Probability-and-statistics -> SOLUTION: Can Iget some help with this problem please.I tried some of it but get stuck. Thanks Kim The recovery rate from the flu is 0.9. If 4 people get the flu waht is the probabilty that      Log On


   

Question 424044: Can Iget some help with this problem please.I tried some of it but get stuck. Thanks Kim
The recovery rate from the flu is 0.9. If 4 people get the flu waht is the probabilty that
all will recover?
0.9^4=.656
at least 2 will recover?
C(4,2)=6 ways
0.9*0.9*0.1*0.1=0.0081
exactly 2 will recover?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The recovery rate from the flu is 0.9.
Probability a person does not recover = 0.1
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If 4 people get the flu what is the probabilty
that all will recover?
0.9^4=.6561
-------------------------
at least 2 will recover?
P(2 <= x <= 4) = 1 - P(0<= x <=1)
= 1 - [0.6561 + 4C1*0.9*0.1^3]
= 1 - [0.6597]
= 0.3403
==============
exactly 2 will recover:
P(x= 2) = 4C2*0.9^2*0.1^2 = 0.0486
==============
Cheers,
Stan H.
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