Exam 4: Basic Probability

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 meaning of probability 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 an adult is ________.

If two events are mutually exclusive,what is the probability that both occur at the same time?

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 and prefers chicken is ________.

TABLE 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 Table 4-4,the probability a randomly selected patron prefers soda is ________.

TABLE 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 Table 4-6,if a randomly selected student has not passed the ELM,the probability the student is not from northern Texas is ________.

Seven passengers are on a waiting list for an overbooked flight.As a result of cancellations,3 seats become available.How many different ways can those 3 available seats be filled regardless of the order?

Simple probability is also called

TABLE 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 Table 4-4,the probability a randomly selected patron is a female is ________.

A company has 2 machines that produce widgets.An older machine produces 23% defective widgets,while the new machine produces only 8% defective widgets.In addition,the new machine produces 3 times as many widgets as the older machine does.What is the probability that a randomly chosen widget produced by the company is defective?

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

TABLE 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 Table 4-6,if a randomly selected student has not passed the ELM,the probability the student is from southern Texas is ________.

If P(A or B)= 1.0,then A and B must be mutually exclusive.

If P(A or B)= 1.0,then A and B must be collectively exhaustive.

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

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 at least $100.00 is ________.

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

If two equally likely events A and B are collectively exhaustive,what is the probability that event A occurs?

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 randomly selected company is a large company,what is the probability that it offered stock options to their board members?

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,what is the probability that a randomly selected worker is white and had claimed bias?