Exam 4: Basic Probability

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

SCENARIO 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 Scenario 4-11,is the preferred source of current information independent of the voting registration status?

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,the probability a randomly selected patron is a female who prefers soda is _____.

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 percentage of the students do not live in a dormitory?

SCENARIO 4-5 In a meat packaging plant Machine A accounts for 60% of the plant's output,while Machine B accounts for 40% of the plant's output.In total,4% of the packages are improperly sealed.Also,3% of the packages are from Machine A and are improperly sealed. -Referring to Scenario 4-5,if a package is selected at random,the probability that it will be properly sealed 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 black and had not claimed bias or is white and has claimed bias?

If P (A and B)= 1,then A and B must be mutually exclusive.

If P(A)= 0.4 and P(B)= 0.6,then A and B must be mutually exclusive.

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?

If two events are independent,what is the probability that they both occur?

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.If the two events are independent,the probability that neither the cost is kept within budget nor the campaign will increase sales is:

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 offered stock options to their board members?

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,the probability a randomly selected patron is a female is _____.

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 unethical practice not to also recommend a class of mutual funds with an exceptionally high probability of loss.

The collection of all possible events is called

Selection of raffle tickets from a large bowl is an example of

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.

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 own 2 cars and have an income over $50,000 a year is:

SCENARIO 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 Scenario 4-11,if an adult is selected at random,what is the probability that he/she is a not a registered voter or does not prefer to get his/her current information from the internet?

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 both of the twin brothers?