Exam 4: Basic Probability

TABLE 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 Table 4-10,if a randomly selected worker had claimed bias,what is the probability that the worker is white?

If P(A and B)= 0,then A and B must be collectively exhaustive.

TABLE 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 Table 4-8,what is the probability that a randomly selected student is a junior or senior who lives in a dormitory?

TABLE 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 Table 4-2,what is the probability that a randomly selected student did well on the midterm or went bar hopping the weekend before the midterm?

TABLE 4-12 Jake woke up late in the morning on the day that he has to go to school to take an important test.He can either take the shuttle bus which is usually running late 20% of the time or ride his unreliable motorcycle which breaks down 40% of the time.He decides to toss a fair coin to make his choice. -Referring to Table 4-12,if Jake,in fact,gets to the test on time,what is the probability that he took the bus?

There are 10 finalists at a national dog show.How many different orders of finishing can there be for all the 10 finalists?

An investment consultant is recommending a certain class of mutual funds to the clienteles based on its exceptionally high probability of gain.It is an ethical practice to explain to the clienteles what the basis of her probability estimate is.

TABLE 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 Table 4-3,the probability that a randomly selected individual is a child or prefers hamburger is ________.

An exploration team of 2 women and 3 men is to be chosen from a candidate pool of 6 women and 7 men.How many different ways can this team of 5 be formed?

There are 47 contestants at a national dog show.How many different ways can contestants fill the first place,second place,and third place positions?

The closing price of a company's stock tomorrow can be lower,higher or the same as today's closed.Without any prior information that may affect the price of the stock tomorrow,the probability that it will close higher than today's close is 1/3.This is an example of using which of the following probability approach?

The probability that a new advertising campaign will increase sales is assessed as being 0.80.The probability that the cost of developing the new ad campaign can be kept within the original budget allocation is 0.40.Assuming that the two events are independent,the probability that the cost is kept within budget and the campaign will increase sales is

The closing price of a company's stock tomorrow can be lower,higher or the same as today's closing price.After evaluating all the information available on the company's fundamentals and the economic environment,an analyst has determined that the probability that tomorrow's closing price will be higher than today's is determined to be 25%.This is an example of using which of the following probability approach?

TABLE 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 Table 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?

TABLE 4-7 The next state lottery will have the following payoffs possible with their associated probabilities. -Referring to Table 4-7,the probability that you win any money is ________.

TABLE 4-11 A sample of 300 adults is selected.The contingency table below shows their registration status and their preferred source of information on current events. -Referring to Table 4-11,if an adult is selected at random,what is the probability that he/she is a registered voter or prefers to get his/her current information from radio?

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?

TABLE 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 Table 4-3,the probability that a randomly selected individual is an adult and prefers chicken is ________.

TABLE 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 Table 4-8,what is the probability that a randomly selected student is a freshman who lives in a dormitory?

According to a survey of American households,the probability that the residents own 2 cars if annual household income is over $50,000 is 80%.Of the households surveyed,60% had incomes over $50,000 and 70% had 2 cars.The probability that the residents of a household do not own 2 cars and have an income over $50,000 a year is