SOLUTION: According to tables provided by the National Center for Health Statistics in Vital Statistics of the United States, there is roughly an 80% chance that a person of age 20 years w

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Question 1190746: According to tables provided by the National Center for Health Statistics in Vital Statistics of the
United States, there is roughly an 80% chance that a person of age 20 years will be alive at age 65
years. Suppose that three people of age 20 years are selected at random. Find the probability that
the number alive at age 65 years will be
A. exactly two.
B. at most one.
C. at least one.
D. Determine the probability distribution of the number alive at age 65.
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
for 0 alive is 0.2^3=0.008
for 1 alive is 3*0.2^2*0.8=0.096
for 2 alive is 3*0.2*0.8^2=0.384
for all 3 it is 0.8^3=0.512
they add to 1, as they should.
answers
a. 0.384
b. is 0 or 1 with prob. 0.104
c. at least 1 is 1- p(0)=0.992
d. The probability distribution is above.
Sometimes it is just easier to write down the whole probability distribution and then answer the questions, when there are several questions. When n is small and the decimals are straightforward, it almost always is easier.