Reading 8: Probability Concepts-LOS f, (Part 3)习题精选 2010, employees, face, company, interpret

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Session 2: Quantitative Methods: Basic Concepts
Reading 8: Probability Concepts

LOS f, (Part 3): Calculate and interpret a joint probability of any number of independent events.

 

 

 

A very large company has equal amounts of male and female employees. If a random sample of four employees is selected, what is the probability that all four employees selected are female?

A) 0.0256

B) 0.0625.

C) 0.1600

zaestau

c

bmaggie

A very large company has twice as many male employees relative to female employees. If a random sample of four employees is selected, what is the probability that all four employees selected are female?

A) 0.0123.

B) 0.3333.

C) 0.0625.

bmaggie

A very large company has twice as many male employees relative to female employees. If a random sample of four employees is selected, what is the probability that all four employees selected are female?

A) 0.0123.

B) 0.3333.

C) 0.0625.

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Since there are twice as many male employees to female employees, P(male) = 2/3 and P(female) = 1/3. Therefore, the probability of 4 “successes” = (0.333)⁴ = 0.0123.

bmaggie

If two events are independent, the probability that they both will occur is:

A) Cannot be determined from the information given.

B) 0.50.

C) 0.00.

bmaggie

If two events are independent, the probability that they both will occur is:

A) Cannot be determined from the information given.

B) 0.50.

C) 0.00.

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If two events are independent, their probability of their joint occurrence is computed as follows:  P(A∩B) = P(A) × P(B). Since we are not given any information on the respective probabilities of A or B, there is not enough information.

bmaggie

A bond portfolio consists of four BB-rated bonds. Each has a probability of default of 24% and these probabilities are independent. What are the probabilities of all the bonds defaulting and the probability of all the bonds not defaulting, respectively?

A) 0.96000; 0.04000.

B) 0.00332; 0.33360.

C) 0.04000; 0.96000.

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For the four independent events where the probability is the same for each, the probability of all defaulting is (0.24)⁴. The probability of all not defaulting is (1 ? 0.24)⁴.

bmaggie

If two fair coins are flipped and two fair six-sided dice are rolled, all at the same time, what is the probability of ending up with two heads (on the coins) and two sixes (on the dice)?

A) 0.8333.

B) 0.4167.

C) 0.0069.

bmaggie

If two fair coins are flipped and two fair six-sided dice are rolled, all at the same time, what is the probability of ending up with two heads (on the coins) and two sixes (on the dice)?

A) 0.8333.

B) 0.4167.

C) 0.0069.

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For the four independent events defined here, the probability of the specified outcome is 0.5000 × 0.5000 × 0.1667 × 0.1667 = 0.0069.

bmaggie

A bond portfolio consists of four BB-rated bonds. Each has a probability of default of 24% and these probabilities are independent. What are the probabilities of all the bonds defaulting and the probability of all the bonds not defaulting, respectively?

A) 0.96000; 0.04000.

B) 0.00332; 0.33360.

C) 0.04000; 0.96000.