SOLUTION: statistics show that 80% of crimes are never solved.suppose a neighborhood district in a large city suffers repeated crimes the police are investigating 6 property crime cases in t

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Question 230971: statistics show that 80% of crimes are never solved.suppose a neighborhood district in a large city suffers repeated crimes the police are investigating 6 property crime cases in this district.
a) what is the probability that none will ever be solved
b0probability at least one will be solved
c0expected # of crimes that will be solved and what is the standard deviation
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
statistics show that 80% of crimes are never solved.suppose a neighborhood district in a large city suffers repeated crimes the police are investigating 6 property crime cases in this district.
a) what is the probability that none will ever be solved
0.8^6 = 0.2621
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b) probability at least one will be solved
P(at least one solved) = 1 - P(none solved) = 1-0.2621 = 0.737856...
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c) expected # of crimes that will be solved and what is the standard deviation
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Expected number = np
Expected number = 6*0.8 = 4.8
Std = sqrt(6*0.8*0.2) = 0.9798
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Cheers,
Stan H.