According to Harper\'s Index , 60% of all federal inmates are serving time for d
ID: 2948653 • Letter: A
Question
According to Harper's Index, 60% of all federal inmates are serving time for drug dealing. A random sample of 16 federal inmates is selected.
(a) What is the probability that 12or more are serving time for drug dealing? (Round your answer to three decimal places.)
(b) What is the probability that 2or fewer are serving time for drug dealing? (Round your answer to three decimal places.)
(c) What is the expected number of inmates serving time for drug dealing? (Round your answer to one decimal place.)
Explanation / Answer
Solution:-
p = 0.60
a) The probability that 12 or more are serving time for drug dealing is 0.167.
x = 12, n = 16
By applying binomial distribution
P(x,n) = nCx*px*(1-p)(n-x)
P(x > 12) = 0.1666
b) The probability that 2 or fewer are serving time for drug dealing is 0.000127.
x = 2, n = 16
By applying binomial distribution
P(x,n) = nCx*px*(1-p)(n-x)
P(x < 2) = 0.000127
c) The expected number of inmates serving time for drug dealing is 9.6.
E(x) = n × p
E(x) = 16 × 0.60
E(x) = 9.6