Exam 2: Probability Concepts and Applications

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.

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?

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 true?

Which of the following is not true for discrete random variables?

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 it will take more than 1/3 of a minute between consecutive drivers?

Given a df₁ = 3 and df₂ = 6,what is the probability that F is greater than 4.3?

The expected value of a probability distribution is

A new young executive is perplexed at the number of interruptions that occur due to employee relations.She has decided to track the number of interruptions that occur during each hour of her day.Over the last month,she has determined that between 0 and 3 interruptions occur during any given hour of her day.The data is shown below. On average,she should expect 0.8 interruptions per hour.

If a bucket has three black balls and seven green balls,and we draw balls without replacement,the probability of drawing a green ball is independent of the number of balls previously drawn.

Arrivals in a university advising office during the week of registration are known to follow a Poisson distribution with an average of 4 people arriving each hour. (a)What is the probability that exactly 4 people will arrive in the next hour? (b)What is the probability that exactly 5 people will arrive in the next hour?

A local "home TV repair service" company has two repairmen who make all of the home repairs.The company sends Repairman D on 70 percent of all jobs,because the likelihood of a "second follow-up call" within a week is only 0.08 compared to 0.20 for Repairman K.If you had a recent repair job that is going to require a second follow-up call,what is the probability that Repairman K did your initial repair work?

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 not enrolled in accounting?

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 less than $85?

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 between 2 and 5 (inclusive)customers are willing to switch companies?

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 fewer than 600 minutes?

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 exactly 2 customers would be willing to switch their cable?

What is the F value associated with α = 0.05,numerator degrees of freedom (df₁)equal to 4,and denominator degrees of freedom (df₂)equal to 9?