Exam 6: Discrete Probability Distributions

A company is studying the number of monthly absences among its 125 employees. The following probability distribution shows the likelihood that people were absent 0,1,2,3,4,or 5 days last month. What is the mode of the distribution?

The production department has installed a new spray machine to paint automobile doors. As is common with most spray guns,unsightly blemishes often appear because of improper mixtures or other problems. A worker counted the number of blemishes on each door. Most doors had no blemishes; a few had one; a very few had two; and so on. The average number was 0.5 per door. The distribution of blemishes followed the Poisson distribution. Out of 10,000 doors painted,about how many would have no blemishes?

In a Poisson distribution,the variance is equal to ________.

What is the only variable in the Poisson probability formula?

The following is a binomial probability distribution with n = 3 and π = 0.20. The mean of the distribution is ________.

Data show that the weight of an offensive linesman may be any weight between 200 and 350 pounds. The distribution of weight is based on a ________.

A total of 60% of the customers of a fast-food chain order a hamburger,french fries,and a drink. If a random sample of 15 cash register receipts is selected,what is the probability that 10 or more will show that the above three food items were ordered?

The probability of a particular outcome must always be between 0.0 and 1.0 inclusive.

Sponsors of a local charity decided to attract wealthy patrons to its $500-a-plate dinner by allowing each patron to buy a set of 20 tickets for the gaming tables. The chance of winning a prize for each of the 20 plays is 50-50. If you bought 20 tickets,what is the chance of winning 15 or more prizes?

The variance of a binomial distribution is found by nπ(1 − π).

The mean of a probability distribution is called its expected value.

David's gasoline station offers 4 cents off per gallon if the customer pays in cash and does not use a credit card. Past evidence indicates that 40% of all customers pay in cash. During a one-hour period,15 customers buy gasoline at this station. This situation is an example of what type of discrete probability distribution?

The mean or expected value for a binomial probability distribution is ________.

The marketing department of a nationally known cereal maker plans to conduct a national survey to find out whether or not consumers of flake cereals can distinguish one of their favorite flake cereals. To test the questionnaire and procedure to be used,eight persons were asked to cooperate in an experiment. Five very small bowls of flake cereals were placed in front of a person. The bowls were labeled A,B,C,D,and E. The person was informed that only one bowl contained his or her favorite flake cereal. Suppose that the eight persons in the experiment were unable to identify their favorite cereal and just guessed which bowl it was in. What is the probability that none of the eight guessed correctly?

A statistics professor receives an average of five e-mail messages per day from students. Assume the number of messages approximates a Poisson distribution. What is the probability that on a randomly selected day she will have no messages?

Which one of the following is NOT a condition of the binomial distribution?

In which of the following discrete distributions does the probability of a success vary from one trial to the next?

A company is studying the number of monthly absences among its 125 employees. The following probability distribution shows the likelihood that people were absent 0,1,2,3,4,or 5 days last month. What is the mean number of days absent?

David's gasoline station offers 4 cents off per gallon if the customer pays in cash and does not use a credit card. Past evidence indicates that 40% of all customers pay in cash. During a one-hour period,15 customers buy gasoline at this station. What is the probability that more than 8 and less than 12 customers pay in cash?