Chapter 4 Book Exercises BUS219:Statistcs

Claudia Pena

September 19, 2023

BUS219

Chapter 4 - Book Exercises

Section 4.1: 

1.) Determine whether the following probabilities are best categorized as subjective, empirical, or classical probabilities.

a. Before flipping a fair coin, Sunil assesses that he has a 50% chance of obtaining tails.

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b. At the beginning of the semester, John believes he has a 90% chance of receiving straight A’s.

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c. A political reporter announces that there is a 40% chance that the next person to come out of the conference room will be a Republican, since there are 60 Republicans and 90 Democrats in the room.

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Section 4.2: Show your work.

11.) Let P(A) = 0.65, P(B) = 0.30, and P(A\B) = 0.45.

a. Calculate P(A ∩ B).

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b. Calculate P(A ∪ B).

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c. Calculate P(B\A).

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Section 4.3:

33.) Consider the following contingency table:

a. Convert the contingency table into a joint probability table.

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b. What is the probability that A occurs?

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c. What is the probability that A and B occur?

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d. Given that B has occurred, what is the probability that A occurs?

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e. Given that Ac has occurred, what is the probability that B occurs?

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f. Are A and B mutually exclusive events? Explain.

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g. Are A and B independent events? Explain.

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Section 4.5:

53.) Twenty cancer patients volunteer for a clinical trial. Ten of the patients will receive a placebo and 10 will receive the trial drug. In how many different ways can the researchers select 10 patients to receive the trial drug from the total of 20?

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