Exam 4: Basic Probability

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 is not from out-of-state,the probability that the student has passed the ELM is ________.

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

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 a randomly selected adult is a registered voter,what is the probability that he/she prefers to get his/her current information from the newspapers?

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

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 percentage of the students live in a dormitory?

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

Suppose A and B are mutually exclusive events where P(A)= 0.4 and P(B)= 0.5.Then P(A and B)= ________.

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 rode his bike?

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 is a female who prefers soda is ________.

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?

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 sophomore who does not live in a dormitory?

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

True or False: If either A or B must occur they are called collectively exhaustive.

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 ________.

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.Assuming that the two events are independent,the probability that the cost is kept within budget or the campaign will increase sales is