Exam 4: Basic Probability

Four freshmen are to be assigned to eleven empty rooms in a student dormitory.All the rooms are considered as homogenous so that it does not matter who is being assigned to which room.How many different ways can those 4 freshmen be assigned?

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,or a child is_____ .

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 the cost is kept within budget and the campaign will increase sales is:

An investment consultant is recommending a certain class of mutual funds to the clienteles based on its exceptionally high probability of exceptionally high gain.It is an unethical practice to tell the clienteles the probability of a loss in her recommendations.

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,if a randomly selected student lives in the dormitory,what is the probability that the student is a freshman?

The collection of all the possible events is called a sample space.

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 prefers to get his/her current information from the internet?

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 selected at random came from Machine B,the probability that it is properly sealed is _____.

If the outcome of event A is not affected by event B,then events A and B are said to be

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

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 a child or prefers hamburger is_____ .

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

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 not from northern Texas is_____ .

There are only 4 empty rooms available in a student dormitory for eleven new freshmen.Each room is considered unique so that it matters who is being assigned to which room.How many different ways can those 4 empty rooms be filled one student per room?

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 is a female.Then the probability the patron prefers water is _____.

Simple probability is also called

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,what is the probability that an adult who prefers to get his/her current information from the internet will be a registered voter?

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 registered voter who prefers to get his/her current information from the television?

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 widget was produced by the new machine,what is the probability it is not defective?

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,assume we know the person is a child.The probability that this individual prefers hamburger is_____ .