Let a two-digit number represent an individual running of the screening test. Which

during a given year, 10 will require repairs twice, and 5 will require three or more repairs during the year. a. What is the probability that a randomly selected car will need no repairs? b. What is the probability that a randomly selected car will need at most one repair? c. What is the probability that a randomly selected car will need some repairs? 4.9 One of the games in the Texas lottery is to pay 1 to select a 3-digit number. Every Wednesday evening, the lottery commission randomly places a set of 10 balls numbered 0 –9 in each of three containers. After a complete mixing of the balls, 1 ball is selected from each container.

a. Suppose you purchase a lottery ticket. What is the probability that your 3-digit number

will be the winning number?

b. Which of the probability approaches subjective, classical, or relative frequency did

you employ in obtaining your answer in part a? 4.3 Basic Event Relations and Probability Laws 4.10 A coin is to be flipped three times. List the possible outcomes in the form result on toss 1, result on toss 2, result on toss 3.

4.11 In Exercise 4.10, assume that each one of the outcomes has probability 1

兾8 of occurring. Find the probability of

a. A: Observing exactly 1 head b. B: Observing 1 or more heads

c. C: Observing no heads 4.12 For Exercise 4.11:

a. Compute the probability of the complement of event A, event B, and event C. b. Determine whether events A and B are mutually exclusive. 4.13 A die is to be rolled and we are to observe the number that falls face up. Find the proba- bilities for these events:

a. A: Observe a 6 b. B: Observe an odd number

c. C: Observe a number greater than 3 d. D: Observe an even number and a number greater than 2

Edu. 4.14 A student has to have an accounting course and an economics course the next term. As- suming there are no schedule conflicts, describe the possible outcomes for selecting one section of the accounting course and one of the economics course if there are four possible accounting sections and three possible economics sections. Engin. 4.15 The emergency room of a hospital has two backup generators, either of which can supply enough electricity for basic hospital operations. We define events A and B as follows: event A: Generator 1 works properly event B: Generator 2 works properly Describe the following events in words:

a. Complement of A b. Either A or B

4.16 The population distribution in the United States based on raceethnicity and blood type as reported by the American Red Cross is given here. Blood Type Race Ethnicity O A B AB White 36 32.2 8.8 3.2 Black 7 2.9 2.5 .5 Asian 1.7 1.2 1 .3 All others 1.5 .8 .3 .1

a. A volunteer blood donor walks into a Red Cross Blood office. What is the probability

she will be Asian and have Type O blood?