37 of adults say cashews are their favorites kind of nuts y
37% of adults say cashews are their favorites kind of nuts . you randomly select 12 adults and ask each to name his/her favorite nuts. find the probability that the number who say cashews are their favorite nuts is
(A) exactly 3 (b) at least 4, and (c) at most two. if convenient , use technology to find the probability
(A) P(3)= round to the nearest thousands as needed
(B) P(x >_ 4)= round to the nearest thousdandth as needed
(C) P(x <_ 2)= round to the nearest thousandth as needed.
Solution
a)
Note that the probability of x successes out of n trials is
P(n, x) = nCx p^x (1 - p)^(n - x)
where
n = number of trials = 12
p = the probability of a success = 0.37
x = the number of successes = 3
Thus, the probability is
P ( 3 ) = 0.174217909 [answer]
b)
Note that P(at least x) = 1 - P(at most x - 1).
Using a cumulative binomial distribution table or technology, matching
n = number of trials = 12
p = the probability of a success = 0.37
x = our critical value of successes = 4
Then the cumulative probability of P(at most x - 1) from a table/technology is
P(at most 3 ) = 0.29466996
Thus, the probability of at least 4 successes is
P(at least 4 ) = 0.70533004 [answer]
c)
Using a cumulative binomial distribution table or technology, matching
n = number of trials = 12
p = the probability of a success = 0.37
x = the maximum number of successes = 2
Then the cumulative probability is
P(at most 2 ) = 0.12045205 [answer]
