BUSI-2305 chapter 5 HW

Suppose P(A) = 0.40 and P(B | A) = 0.30. What is the joint probability of A and B? (Round your answer to 2 decimal places.)

.12 0.4×0.3=0.12

Suppose the probability you will get an A in this class is 0.25 and the probability you will get a B is 0.50. What is the probability your grade will be above a C? (Round your answer to 2 decimal places.)

0.75

An investor buys 100 shares of AT&T stock, and records its change in price daily. Which concept of probability would you most closely associate with recording and tracking the daily change in the price of the stock? *empirical *classical

Empirical

All Seasons Plumbing has two service trucks that frequently need repair. If the probability the first truck is available is 0.75, the probability the second truck is available is 0.50, and the probability that both trucks are available is 0.30, what is the probability neither truck is available? (Round your answer to 2 decimal places.)

P(A)=0.75. P(B)=0.5 and P(A and B)=0.3 P(A or B)​=P(A)+P(B)−P(A and B) =0.75+0.5−0.3 =0.95​ P(Neither A nor B)​=1−P(A or B) =1−0.95 =0.05​

A telephone number consists of seven digits, the first three representing the exchange. How many different telephone numbers are possible within the 537 exchange?

number of possible telephone numbers is 10000

Some people are in favor of reducing federal taxes to increase consumer spending and others are against it. Two persons are selected and their opinions are recorded. Assume no one is undecided. Find the number of possible outcomes.

There are 4following outcomes: (favour, favour), (favour, against), (against, against), (against, favour) where the first value represent the first person's opinion and the second one represents second person's opinion.

The events A and B are mutually exclusive. Suppose P(A)=0.30 and P(B)=0.20. a. What is the probability of either A or B occurring? (Round your answer to 2 decimal places.) b. What is the probability that neither A nor B will happen? (Round your answer to 2 decimal places.)

a. 0.50 b. 0.50

A survey of 545 college students asked: What is your favorite winter sport? And, what type of college do you attend? The results are summarized below: Favorite Winter Sport College Type Snow boarding Skiing Ice Skating Total Junior College 68 41 46 155 Four-Year College 84 56 70 210 Graduate School 59 74 47 180 Total 211 171 163 545 Using these 545 students as the sample, a student from this study is randomly selected. a. What is the probability of selecting a student whose favorite sport is skiing?(Round your answer to 4 decimal places.) b. What is the probability of selecting a junior-college student?(Round your answer to 4 decimal places.) c. If the student selected is a four-year-college student, what is the probability that the student prefers ice skating?(Round your answer to 4 decimal places.) d. If the student selected

a. 171/545=0.3138 b. 155/545 = 0.2844 c. 70/210 = 0.3333 d. 68/211 = 0.3223 e. 74/180 = 0.4111 47/180 = 0.2611 0.4111 + 0.2611 = 0.6722

A case of 24 cans contains one can that is contaminated. Three cans are to be chosen randomly for testing. a. How many different combinations of three cans could be selected? b. What is the probability that the contaminated can is selected for testing? (Round your answer to 3 decimal places.)

a. 24C3​ =24!​/3!(24−3)! =24×23×22/3×2 ​=2024. b. =23C2=23!/(23-2)!2! =253 Probability =253/2024 =0.125

Solve the following: a.40!/35! b.7P4 c.5C2

a. 40⋅39⋅38⋅37⋅36⋅35!​/35! =40⋅39⋅38⋅37⋅36/1 ​=78960960​​ b.=7!/(7−4)!​ =7!/3!​ =7⋅6⋅5⋅4⋅3!/3! ​=7⋅6⋅5⋅4 =840​​ c.=5!/2!(5−2)!​ =5!/2!3!​ =5⋅4⋅3!/2⋅1⋅3!​ =5⋅4​/2⋅1 =20/2 ​=10​​ note: blue colored numbers = marked out

A new sports car model has defective brakes 15% of the time and a defective steering mechanism 5% of the time. Let's assume (and hope) that these problems occur independently. If one or the other of these problems is present, the car is called a "lemon." If both of these problems are present, the car is a "hazard." Your instructor purchased one of these cars yesterday. a. What is the probability it is a lemon? (Round your answer to 3 decimal places.) b. What is the probability it is a hazard? (Round your answer to 3 decimal places.)

a. P(A or B)​=P(A)+P(B)−P(A and B) =P(A)+P(B)−P(A)P(B) =0.15+0.05−0.15×0.05 =0.2−0.0075 =0.1925​ b. P(A and B)​=P(A)P(B) =0.15×0.05 =0.0075​

For the daily lottery game in Illinois, participants select three numbers between 0 and 9. A number cannot be selected more than once, so a winning ticket could be, say, 307 but not 337. Purchasing one ticket allows you to select one set of numbers. The winning numbers are announced on TV each night. a. How many different outcomes (three-digit numbers) are possible? b. If you purchase a ticket for the game tonight, what is the likelihood you will win? (Round your answer to 4 decimal places.) c. Suppose you purchase three tickets for tonight's drawing and select a different number for each ticket. What is the probability that you will not win with any of the tickets? (Round your answer to 4 decimal places.)

a. P3=10! 10x9x8= 720 b. P(you win the game)​=Number of favorable outcomes/Total number of outcomes​ =1/648​ =0.00154​ c. Probability that you don not win on first ticket × Probability that you don not win on second ticket × Probability that you don not win on third ticket =(1−0.00154) × (1−0.00154) × (1−0.00154) =0.9954​

A sample of 40 oil industry executives was selected to test a questionnaire. One question about environmental issues required a "yes" or "no" answer. a. What is the experiment? The survey of people about environmental issue. b. Which of the following are possible events. (You may select more than one answer. Single click the box with the question mark to produce a check mark for a correct answer and double click the box with the question mark to empty the box for a wrong answer.) *26 people respond *30 people respond *26 people respond *41 people respond *The questionnaire fails to reach one executive. *The questionnaire reaches all 40 executives. c. Ten of the 40 executives responded "yes". Based on these sample responses, what is the probability that an oil industry executive will respond "yes"? (Round your answer to 2 decimal places.) Probability d. What concept of probability does this illustrate? multiple choice *Classical *Empirical *Neither e. Are each of the possible outcomes equally likely and mutually exclusive? multiple choice *The outcomes are not equally likely but are mutually exclusive. *The outcomes are not equally likely and are also no

a. The survey of 40 people about environmental issues. b. *26 people respond yes *30 people respond yes *26 people respond no *The questionnaire fails to reach one executive. *The questionnaire reaches all 40 executives c. 0.25 d. empirical e. The outcomes are equally likely and are also mutually exclusive.

A survey of 34 students at the Wall College of Business showed the following majors: Accounting 10 Finance 5 Economics 3 Management 6 Marketing 10 From the 34 students, suppose you randomly select a student. a.What is the probability he or she is a management major?(Round your answer to 3 decimal places.) b. Which concept of probability did you use to make this estimate? multiple choice Classical Empirical Inference Randomness Uniformity

a. With the number of management major and the total number of students surveyed, we simply divide 6 by 34 to obtain the probability P​=6/34​=0.1765​ b. Empirical probability is used for estimating the above probability since the probability is calculated using the information available to us.

Each salesperson at Puchett, Sheets, and Hogan Insurance Agency is rated either below average, average, or above average with respect to sales ability. Each salesperson is also rated with respect to his or her potential for advancement—either fair, good, or excellent. These traits for the 500 salespeople were cross-classified into the following table. Potential for Advancement Sales Ability Fair Good Excellent Below average 16 12 22 Average 45 60 45 Above average 93 72 135 a.What is this table called? multiple choice Bayesian table Contingency table Probability table b.What is the probability a salesperson selected at random will have above average sales ability and excellent potential for advancement?(Round your answer to 2 decimal places.) c.Fill in the blanks to provide details for a tree diagram.(Round your answers to 3 decim

a. contingency table b. P (Above average and Excellent)​=# of favorable outcome/ # of possible outcomes ​=135/500 ​=27/100 ​=0.27 c. look at picture

In each of the following cases, indicate whether classical, empirical, or subjective probability is used. a. A baseball player gets a hit in 30 out of 100 times at bat. The probability is 0.30 that he gets a hit in his next at bat. multiple choice Empirical Subjective Classical b. A seven-member committee of students is formed to study environmental issues. What is the likelihood that any one of the seven is randomly chosen as the spokesperson? multiple choice Empirical Subjective Classical c. You purchase a ticket for the Lotto Canada lottery. Over five million tickets were sold. What is the likelihood you will win the $1 million jackpot? multiple choice Empirical Subjective Classical d. The probability of an earthquake in northern California in the next 10 years above 5.0 on the Richter Scale is 0.80. multiple choice Empirical Subjective Classical

a. empirical b. classical c. classical d. empirical

A firm will promote two employees out of a group of six men and three women. What probability concept would be used to assign probabilities to the outcomes? classical empirical

classical