Exam 2: Probability Concepts and Applications

In a given office, the color printer breaks down with a probability of 20% in any month. A binomial process is assumed for a period of 10 months. (a) What is the probability that the printer breaks down exactly 2 times? (b) What is the probability that the printer breaks down at most 1 time? (c) What is the probability that the printer breaks down more than once?

In what way is the F distribution often used?

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.

If the sale of ice cream and pizza are independent, then as ice cream sales decrease by 60 percent during the winter months, pizza sales will

The time required to complete a project is normally distributed with a mean of 80 weeks and a standard deviation of 10 weeks. The construction company must pay a penalty if the project is not finished by the due date in the contract. If a construction company bidding on this contract wishes to be 90 percent sure of finishing by the due date, what due date (project week #) should be negotiated?

The time required to complete a project is known to be normally distributed with a mean of 44 weeks and a standard deviation of 8 weeks. (a) What is the probability that the project is finished in 40 weeks or fewer? (b) What is the probability that the project is finished in 52 weeks or fewer? (c) There is an 95 percent chance that the project will be finished in fewer than how many weeks?

Suppose that 10 golfers enter a tournament and that their respective skill levels are approximately the same. Six of the entrants are female and two of those are older than 40 years old. Three of the men are older than 40 years old. What is the probability that the winner will be either female or older than 40 years old?

Properties of the normal distribution include

The number of cars passing through an intersection in the next five minutes can usually be described by the

Assume that you have an urn containing 10 balls of the following description: 4 are white (W) and lettered (L) 2 are white (W) and numbered (N) 3 are yellow (Y) and lettered (L) 1 is yellow (Y) and numbered (N) If you draw a numbered ball (N), the probability that this ball is white (W) is 0.667.

The Department of Motor Vehicles (DMV) can service customers at a rate of 20 per hour (or 1/3 per minute) when it comes to license renewals. The service time follows an exponential distribution. What is the probability that it will take less than 3 minutes for a particular customer to get a license renewal?

Given the following distribution: The expected value is 3.

A posterior probability is a revised probability.

Drivers arrive at a toll booth at a rate of 3 per minute during peak traffic periods. The time between consecutive driver arrivals follows an exponential distribution. What is the probability that takes less than 1/2 of a minute between consecutive drivers?

Historical data indicates that only 20% of cable customers are willing to switch companies. If a binomial process is assumed, then in a sample of 20 cable customers, what is the probability that no more than 3 customers would be willing to switch their cable?

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 that a customer uses only one of these services?

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 and found to be enrolled in statistics, what is the probability that the student is also enrolled in accounting?

When does P(A|B) = P(A)?

Which of the following characteristics is true for a normal probability distribution?

Given two statistically dependent events (A,B), the conditional probability of P(A|B) = P(B)/P(AB).