SOLUTION: Assume that 37% of the emails that come into your personal email account are spam. You pick at random 7 emails. Find the probability that: a) 3 are spam b) all are spam c) non

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Question 913728: Assume that 37% of the emails that come into your personal email account are spam. You pick at
random 7 emails. Find the probability that:
a) 3 are spam
b) all are spam
c) none are spam
d) What is the expected number of spam emails in the 7 emails?

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
p(spam) = .37, n = 7
P(x=3) = binompdf(7, .37, 3) 0r P = 7C3(.37)^3(.63)^4
P(x = 7) = binompdf(7, .37, 7) 0r P = (0.37)^7
P(x = 0) = (.63)^7
d) expected = .37%2A7