Exam 5: Discrete Probability Distributions

Exhibit 5-6.The number of cars sold by a car salesman during each of the last 25 weeks is the following: Refer to Exhibit 5-6.What is the probability that the salesman sells no more than one car during a week?

A continuous random variable X assumes an (infinitely)uncountable number of distinct values.

Four of your students submitted an entry to a writing contest.There were a total of 24 entries submitted.Six of the entries will move on to the next round. A)What is the probability that all four of your students will move on to the next round? B)How many of your students are expected to move to the next round? C)What is the probability that fewer of your students than expected make it to the next round than expected?

Which of the following statements is most accurate about a binomial random variable?

Due to turnover and promotion,a bank manager knows that,on average,she hires four new tellers per year.Suppose the number of tellers she hires is Poisson-distributed. A)What is the probability that in a given year,the manager hires exactly five new tellers? B)What is the average number of tellers the manager hires in a six-month period? C)What is the probability that the manager hires at least one new teller in a given six-month period?

Exhibit 5-12.According to a Department of Labor report,the city of Detroit had a 20% unemployment rate in May of 2011 (Bureau of Labor Statistics,May,2011).Eight working-age residents were chosen at random. Refer to Exhibit 5-12.What is the probability that exactly one of the residents was unemployed?

Exhibit 5-1.Consider the following discrete probability distribution. Refer to Exhibit 5-1.What is the probability that X is less than 5?

Exhibit 5-5.The number of homes sold by a realtor during a month has the following probability distribution: Refer to Exhibit 5-5.What is the probability that the realtor will sell at least one house during a month?

It is known that 10% of the calculators shipped from a particular factory are defective.What is the probability that at least one in a random sample of four calculators is defective?

Does the following table describe a discrete probability distribution?

Exhibit 5-12.According to a Department of Labor report,the city of Detroit had a 20% unemployment rate in May of 2011 (Bureau of Labor Statistics,May,2011).Eight working-age residents were chosen at random. Refer to Exhibit 5-12.What is the probability that at least two of the residents were unemployed?

A telemarketer knows that,on average,he is able to make three sales in a 30-minute period.Suppose the number of sales he can make in a given time period is Poisson-distributed. A)What is the probability that he makes exactly four sales in a 30-minute period? B)What is the probability that he makes at least two sales in a 30-minute period? C)What is the probability that he makes five sales in an hour-long period?

A consumer who is risk averse is best characterized as _______________.

Exhibit 5-16.According to geologists,the San Francisco Bay Area experiences five earthquakes with a magnitude of 6.5 or greater every 100 years. Refer to Exhibit 5-16.What is the probability that more than two earthquakes with a magnitude of 6.5 or greater will strike the San Francisco Bay Area in the next 40 years?

Exhibit 5-11.For a particular clothing store,a marketing firm finds that 16% of $10-off coupons delivered by mail are redeemed.Suppose six customers are randomly selected and are mailed $10-off coupons. Refer to Exhibit 5-11.What is the probability that no more than one of the customers redeems the coupon?

Thirty percent of the CFA candidates have a degree in economics.A random sample of three CFA candidates is selected.What is the probability that at least one of them has a degree in economics?

It is known that 10% of the calculators shipped from a particular factory are defective.What is the probability that none in a random sample of four calculators is defective?

An urn contains 12 balls,5 of which are red.The selection of a red ball is desired and is therefore considered to be a success.If a person draws three balls from the urn,what is the probability of two successes?

Which of the following statements is most accurate about a Poisson random variable?

An urn contains 12 balls,5 of which are red.Selection of a red ball is desired and is therefore considered to be a success.If three balls are selected,what is the expected value of the distribution of the number of selected red balls?