Exam 2: Probability Concepts and Applications

The probability,P,of any event or state of nature occurring is greater than or equal to 0 and less than or equal to 1.

The exponential distribution often describes ________.

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?

ABC Manufacturing has 6 machines that perform a particular task.Breakdowns occur frequently for this machine.Past records indicate that the number of breakdowns that occur each day is described by the following probability distribution: (a)What is the expected number of breakdowns in any given day? (b)What is the variance for this distribution? (c)What is the probability that there will be at least 2 breakdowns in a day?

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 enrolled in statistics?

A production process is known to produce a particular item in such a way that 5 percent of these are defective.If two items are randomly selected as they come off the production line,what is the probability that both are defective (assuming that they are independent)?

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

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

The number of cell phone minutes used by high school seniors follows a normal distribution with a mean of 500 and a standard deviation of 50.What is the probability that a student uses more than 350 minutes?

Mutually exclusive events exist if only one of the events can occur on any one trial.

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 enrolled in neither accounting nor statistics?

Given the following distribution: The expected value is 3.

Given two statistically independent events (A,B),the conditional probability P(A|B)= P(A).

A company is considering producing two new electronic games designed for the popular Gameboy toy.Based on market data,management believes that there is a 60 percent chance that a "cops and robbers" game will be successful and a 40 percent chance that a "let's play house" game will be successful.As these products are completely different,it may be assumed that the success of one is totally independent of the success of the other.If two products are introduced to the market,what is the probability that both are failures?

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 results indicate a successful market for the product and the product is actually not successful?

Customer arrivals occur at a rate of 1.2 per minute.The time between customer arrivals follows an exponential distribution.What is the probability that it takes between 1 and 2 minutes between customer arrivals?

Suppose that you enter a drawing by obtaining one of 20 tickets that have been distributed.By using the classical method,you can determine that the probability of your winning the drawing is 0.05.

For two events A and B that are not mutually exclusive,the probability that either A or B will occur is P(A)× P(B)- P(A and B).

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.

The equation P(A|B)= P(AB)/P(B)is