Exam 4: Basic Probability

SCENARIO 4-8 According to the record of the registrar's office at a state university,35% of the students are freshman,25% are sophomore,16% are junior and the rest are senior.Among the freshmen,sophomores,juniors and seniors,the portion of students who live in the dormitory are,respectively,80%,60%,30% and 20%. -Referring to Scenario 4-8,what is the probability that a randomly selected student is a sophomore who does not live in a dormitory?

The employees of a company were surveyed on questions regarding their educational background (college degree or no college degree)and marital status (single or married).Of the 600 employees,400 had college degrees,100 were single,and 60 were single college graduates.The probability that an employee of the company is single or has a college degree is:

If P (A and B)= 1,then A and B must be collectively exhaustive.

Suppose A and B are independent events where P(A)= 0.4 and P(B)= 0.5.Then P (A and B)= .

At the International Pancakes Hut,there are 4 different ways to have an egg cooked,7 different choices of pancakes,5 different types of syrups and 8 different beverages.How many different ways are there to order an egg,a pancake with a choice of syrup and a beverage?

SCENARIO 4-9 A survey conducted by the Segal Company of New York found that in a sample of 189 large companies,40 offered stock options to their board members as part of their non-cash compensation packages.For small- to mid-sized companies,43 of the 180 surveyed indicated that they offer stock options as part of their noncash compensation packages to their board members. -Referring to Scenario 4-9,if a company is selected at random,what is the probability that the company is small to mid-sized and did not offer stock options to their board members?

SCENARIO 4-3 A survey is taken among customers of a fast-food restaurant to determine preference for hamburger or chicken.Of 200 respondents selected,75 were children and 125 were adults.120 preferred hamburger and 80 preferred chicken.55 of the children preferred hamburger. -Referring to Scenario 4-3,the probability that a randomly selected individual is an adult is_____.

If either A or B must occur they are called mutually exclusive.

SCENARIO 4-10 Are whites more likely to claim bias? It was found that 60% of the workers were white,30% were black and 10% are other races.Given that a worker was white,the probability that the worker had claimed bias was 30%.Given that a worker was black,the probability that the worker had claimed bias was 40%.Given that a worker was other race,the probability that the worker had claimed bias was 0%. -Referring to Scenario 4-10,if a randomly selected worker had claimed bias,what is the probability that the worker is white?

When using the general multiplication rule,P (A and B)is equal to

All the events in the sample space that are not part of the specified event are called

A debate team of 4 is to be chosen from a class of 35.There are two twin brothers in the class.How many possible ways can the team be formed which will include only one of the twin brothers?

SCENARIO 4-4 Suppose that patrons of a restaurant were asked whether they preferred water or whether they preferred soda.70% said that they preferred water.60% of the patrons were male.80% of the males preferred water. -Referring to Scenario 4-4,suppose a randomly selected patron prefers soda.Then the probability the patron is a male is _____.

SCENARIO 4-2 An alcohol awareness task force at a Big-Ten university sampled 200 students after the midterm to ask them whether they went bar hopping the weekend before the midterm or spent the weekend studying,and whether they did well or poorly on the midterm.The following result was obtained. -Referring to Scenario 4-2,what is the probability that a randomly selected student who went bar hopping did well on the midterm?

To ethically advertise a school lottery scheme to try to raise money for the athletic department,the organizer of the lottery does not need to explicitly specify the probability of each of the prize in the lottery.

SCENARIO 4-8 According to the record of the registrar's office at a state university,35% of the students are freshman,25% are sophomore,16% are junior and the rest are senior.Among the freshmen,sophomores,juniors and seniors,the portion of students who live in the dormitory are,respectively,80%,60%,30% and 20%. -Referring to Scenario 4-8,what is the probability that a randomly selected student is a freshman who lives in a dormitory?

SCENARIO 4-6 At a Texas college,60% of the students are from the southern part of the state,30% are from the northern part of the state,and the remaining 10% are from out-of-state.All students must take and pass an Entry Level Math (ELM)test.60% of the southerners have passed the ELM,70% of the northerners have passed the ELM,and 90% of the out-of-staters have passed the ELM. -Referring to Scenario 4-6,if a randomly selected student has not passed the ELM,the probability the student is from southern Texas is_____ .

SCENARIO 4-10 Are whites more likely to claim bias? It was found that 60% of the workers were white,30% were black and 10% are other races.Given that a worker was white,the probability that the worker had claimed bias was 30%.Given that a worker was black,the probability that the worker had claimed bias was 40%.Given that a worker was other race,the probability that the worker had claimed bias was 0%. -Referring to Scenario 4-10,what is the probability that a randomly selected worker is not black and had not claimed bias?

A new model car from Ford Motor Company offers a keyless entry system that utilizes a four- letter code.How many different possible combinations are there for the code?

Twelve students in a Business Statistics class are to be formed into three teams of four.How many different ways can this be done?