If 60% of the population of the United States need to have
their vision corrected, we say that the probability that an individual chosen
at random from the population needs vision correction is 
(
) =
0.60.
a. Estimate the probability that an individual chosen at
random does not need vision correction. Hint: Use the complement of a
probability.
b. If 3 people are chosen at random from the population,
what is the probability that all 3 need correction, P(CCC)?
Hint: Use the multiplication law of probability for independent events.
c. If 3 people are chosen at random from the population,
what is the probability that the second person does not need correction but the
first and the third do, P(CNC)?
d. If 3 people are chosen at random from the population,
what is the probability that 1 out of the 3 needs correction, P(CNN or
NCN or NNC)? Hint: Use the addition law of probability for
mutually exclusive events.
e. Assuming no association between vision and gender, what
is the probability that a randomly chosen female needs vision correction, P(CjF)?