Probability: Written Problem Set 2

1. In a study of fatal car accidents, some accidents were attributed to high speed or drunk driving.

1. The probability that the fatality was attributed to high speeds was 0.57.
2. The probability that the fatality was attributed to drunk driving was 0.62.
3. The probability that high speed and drunk driving caused the accident was 0.41.

a. [1 pt] What is the probability that a fatal accident will be attributed to high speeds or drunk driving?

(Grade breakdown: .25 for correct answer; .25 for correct work; .5 for reasoning)

Replace the italicized words with your image of the solution, answer and explanation.

(for question 1a only)

b. [2 pts] What is the probability that a fatal accident will be attributed to neither cause?

(Grade breakdown: .5 for correct answer; .5 for correct work; 1 for reasoning)

Replace the italicized words with your image of the solution, answer and explanation.

(for question 1b only)

c. [2 pts] What is the probability that the fatality will be attributed to drunk driving, but not high speeds?

(Grade breakdown: .5 for correct answer; .5 for correct work; 1 for reasoning)

Replace the italicized words with your image of the solution, answer and explanation.

(for question 1c only)

2. 1522 customers at a major retailer were surveyed whether or not they made a purchase and were satisfied with the service they received. The table below organizes the responses.

	Satisfied with Service	Not Satisfied with Service	Total
Made a Purchase	130	494	624
Did Not Make a Purchase	715	183	898
Total	845	677	1522

a. [2 pts] What is the probability that a shopper selected at random made a purchase, given that they were not satisfied with the service? Write your answer as a fraction.

(Grade breakdown: 1 for correct answer; 1 for reasoning)

Replace the italicized words with your image of the solution, answer and explanation.

(for question 2a only)

b. [1 pt] What is the probability that a shopper selected at random made a purchase or was satisfied with the service they received? Write your answer as a fraction.

(Grade breakdown: .5 for correct answer; .5 for reasoning)

Replace the italicized words with your image of the solution, answer and explanation.

(for question 2b only)

c. [2 pts] What is the probability that a shopper selected at random was not satisfied with the service, given that they made a purchase? Write your answer as a fraction.

(Grade breakdown: 1 for correct answer; 1 for reasoning)

Replace the italicized words with your image of the solution, answer and explanation.

(for question 2c only)