Exam 2: Probability Concepts and Applications

Saying that a set of events is collectively exhaustive implies that one of the events must occur.

A dry cleaning business offers a pick-up and delivery service for a 10 percent surcharge.Management believes 60 percent of the existing customers will take advantage of this service.They are also considering offering customers the option of opening an account and receiving monthly bills.They believe 60 percent of customers (regardless of whether or not they use the pick-up service)will use the account service.If the two services are introduced to the market, what is the probability a customer uses neither of these services?

A company is considering producing some new Gameboy electronic games.Based on past records, management believes that there is a 70 percent chance that each of these will be successful, and a 30 percent chance of failure.Market research may be used to revise these probabilities.In the past, the successful products were predicted to be successful based on market research 90 percent of the time.However, for products that failed, the market research predicted these would be successes 20 percent of the time.If market research is performed for a new product, what is the probability that the product will be successful if the market research indicates a success?

For df₁ = 4 and df₂ = 5, what is the probability that F is greater than 4.5?

"The probability of event B, given that event A has occurred" is known as a ________ probability.

Data for a particular subdivision near downtown Houston indicate that the average price per square foot for a home is $100 with a standard deviation of $5 (normally distributed).What is the probability that the average price per square foot for a home is greater than $90?

A market research study is being conducted to determine if a product modification will be well received by the public.A total of 1,000 consumers are questioned regarding this product.The table below provides information regarding this sample. (a)What is the probability that a randomly selected male would find this change unfavorable (negative)? (b)What is the probability that a randomly selected person would be a female who had a positive reaction? (c)If it is known that a person had a negative reaction to the study, what is the probability that the person is male?

The mean and standard deviation of the Poisson distribution are equal.

Our department store is having a sale on personal computers, of which three are in stock (no rain checks).There is a certain probability of selling none.The probability of selling one is twice as great as the probability of selling none.The probability of selling two is three times the probability of selling none.Finally, the probability of selling all the personal computers is four times as great as the probability of selling none.In a table, list the outcomes and their probabilities.Hint: Let the probability of selling none equal x.

If two events (A,B)are independent, what is their joint probability?

Which distribution is helpful in testing hypotheses about variances?

A conditional probability P(B|A)is equal to its marginal probability P(B)if

At a university with 1,000 business majors, there are 200 business students enrolled in an introductory statistics course.Of these 200 students, 50 are also enrolled in an introductory accounting course.There are an additional 250 business students enrolled in accounting but not enrolled in statistics.If a business student is selected at random, what is the probability that the student is either enrolled in accounting or statistics, but not both?

The number of defects that occur per unit of product follows a Poisson distribution with a mean of 4 defects per unit.What is the standard deviation of this distribution?

A consulting firm has received 2 Super Bowl playoff tickets from one of its clients.To be fair, the firm is randomly selecting two different employee names to "win" the tickets.There are 6 secretaries, 5 consultants and 4 partners in the firm.Which of the following statements is not true?