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,when a randomly selected worker was not white,what is the probability that the worker had not claimed bias?

A business venture can result in the following outcomes (with their corresponding chance of occurring in parentheses): Highly Successful (10%),Successful (25%),Break Even (25%),Disappointing (20%),and Highly Disappointing (?).If these are the only outcomes possible for the business venture,what is the chance that the business venture will be considered Highly Disappointing?

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

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,the probability that a randomly selected student is not from southern Texas and has not passed the ELM 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?

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 that a randomly selected patron prefers soda is ________.

If two events are mutually exclusive and collectively exhaustive,what is the probability that one or the other occurs?

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

TABLE 4-1 Mothers Against Drunk Driving is a very visible group whose main focus is to educate the public about the harm caused by drunk drivers.A study was recently done that emphasized the problem we all face with drinking and driving.Four hundred accidents that occurred on a Saturday night were analyzed.Two items noted were the number of vehicles involved and whether alcohol played a role in the accident.The numbers are shown below: -Referring to Table 4-1,given that alcohol was not involved,what proportion of the accidents were multiple vehicle?

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,if a randomly selected student does not live in the dormitory,what is the probability that the student is a junior or a senior?

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.Given that a randomly chosen widget was tested and was found to be defective,what is the probability that it was produced by the new machine?

True or False: Referring to Table 4-4,the two events "preferring water" and "being a male" are independent.

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,is the preferred source of current information independent of the voting registration status?

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

True or False: When A and B are mutually exclusive,P(A or B)can be found by adding P(A)and P(B).

Simple probability is also called

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,the events "Did Well on Midterm" and "Did Poorly on Midterm" are

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 noncash 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 offered stock options to their board members?

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 married and has a college degree is

Suppose A and B are events where P(A)= 0.4,P(B)= 0.5,and P(A and B)= 0.1.Then P(A or B)= ________.