Question

A budgeting Web site reported that 20 % of U.S. households have withdrawn money from a 401(k) or other retirement account for needs other than retirement in 2013. A random sample of 11 U.S. households was selected. Complete parts a through e below.

Round to 4 decimal places

a)What is the probability that exactly three households withdrew funds from a retirement account for needs other than retirement?

b.What is the probability that less than three households withdrew funds from a retirement account for needs other than retirement?

c. What is the probability that more than four households withdrew funds from a retirement account for needs other than retirement?

d. What are the mean and standard deviation for this distribution?

e.Construct a histogram for this distribution

Answer 1

This is a binomial distribution question with
n = 11
p = 0.2
q = 1 - p = 0.8
where

a) x = 3

P(X = 3) = 0.2215
b) x = 3
P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2)

P(X < 3) = 0.6174
c) x = 4

P(X > 4) = 0.0504
d) Since we know that

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