The mayor of a large U.S. city has a 35% favorability rating.
This means 35% of the people in the city believe he is doing a good
job. Suppose we randomly select citizen subjects from the city, one
by one, and ask if the mayor is doing a good job. Let X equal the
number of unfavorable ratings we get until we get our first
favorable rating. Let Y equal the number of unfavorable ratings we
encounter until we get our 3rd favorable rating.
a. What is the probability X=4?
b. What is the variance of X?
c. What is the probability that X > 10?
d. What is the probability that X ≤ 4?
e. What is the probability that Y = 8?
f. What is the probability that X = 0
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