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Math 166 Quiz 7: 2.3, 2.4, 3.1
Remember to show your work. Correct math is worth partial credit.
1. (3 points) An experiment is to form ”words” using all of the letters in pprmmtsss. What is
the probability of a ”word” having a p next to an m?
2. (4 points) An urn contains 1 black marble, 6 green marbles, and 2 red marbles. A sample of
7 is chosen. Let the random variable X denote the number of red or black marbles. Find the
probability distribution for X.
3. (3 points) The average American spends 5 hours a day watching television. If we randomly
select 15 Americans to be called at a randomly selected time during the day, what is the
probability that at least 7 but fewer than 10 of the people polled are watching television when
they were called?
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