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,what is the probability that a randomly selected worker is black and had not claimed bias or is white and has claimed bias?

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

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?

If P(A)= 0.4 and P(B)= 0.6,then A and B must be collectively exhaustive.

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 company is selected at random,what is the probability that the company offered stock options to their board members?

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,set up a contingency table.

The probability that house sales will increase in the next 6 months is estimated to be 0.25.The probability that the interest rates on housing loans will go up in the same period is estimated to be 0.74.The probability that house sales or interest rates will go up during the next 6 months is estimated to be 0.89.The events increase in house sales and increase in interest rates in the next 6 months are

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 the student has passed the ELM is ________.

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 company is selected at random,what is the probability that the company is small to mid-sized or offered stock options to their board members?

TABLE 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 Table 4-5,if a package selected at random came from Machine B,the probability that it is properly sealed is ________.

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 do not live in a dormitory?

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

There are only 4 empty rooms available in a student dormitory for eleven new freshmen.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 empty rooms be filled one student per room?

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

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 not include any of the twin brothers?

The probability that house sales will increase in the next 6 months is estimated to be 0.25.The probability that the interest rates on housing loans will go up in the same period is estimated to be 0.74.The probability that house sales or interest rates will go up during the next 6 months is estimated to be 0.89.The probability that house sales will increase but interest rates will not during the next 6 months is

The closing price of a company's stock tomorrow can be lower,higher or the same as today's closing price.Based on the closing price of the stock collected over the last month,25% of the days the closing price was higher than previous day's closing price,45% was lower than previous day's and 30% was the same as previous day's.Based on this information,the probability that tomorrow's closing price will be higher than today's is 25%.This is an example of using which of the following probability approach?

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

If event A and event B cannot occur at the same time,then events A and B are said to be

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,determine whether the class status of a student and whether the student lives in a dormitory are independent.