Exam 2: Probability Concepts and Applications

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 statistics?

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 580 minutes?

Which of the following characteristics is not true for the exponential distribution?

The time required to travel downtown at 10 a.m.on Monday morning is known to be normally distributed with a mean of 40 minutes and a standard deviation of 5 minutes.What is the probability that it will take more than 40 minutes?

Suppose that 10 golfers enter a tournament and that their respective skill levels are approximately the same.What is the probability that one of the first three golfers that registered for the tournament will win?

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 a customer uses neither of these services?

The length of time that it takes the tollbooth attendant to service each driver can typically be described by the

Suppose that when the temperature is between 35 and 50 degrees,it has historically rained 40% of the time.Also,historically,the month of April has had a temperature between 35 and 50 degrees on 25 days.You have scheduled a golf tournament for April 12.What is the probability that players will experience rain and a temperature between 35 and 50 degrees?

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 1.0 interruptions per hour.

For df₁ = 4 and df₂ = 5,what is the probability that F is greater than 4.5?

An urn contains 7 blue and 3 yellow chips.If the drawing of chips is done with replacement,determine the probability of: (a)drawing three yellow chips. (b)drawing a blue chip on the first draw and a yellow chip on the second draw. (c)drawing a blue chip on the second draw given that a yellow chip was drawn on the first draw. (d)drawing a yellow chip on the second draw given that a blue chip was drawn on the first draw. (e)drawing a yellow chip on the second draw given that a yellow chip was drawn on the first draw.

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 an unsuccessful market for the product and the product is actually successful?

The expected value of a binomial distribution is expressed as np,where n equals the number of trials and p equals the probability of success of any individual trial.

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 puts in a due date of 80 weeks,what is the probability that they will have to pay a penalty?

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 a female who is older than 40 years old?

Suppose that we determine the probability of a warm winter based on the number of warm winters experienced over the past 10 years.In this case,we have used

Arrivals at a fast-food restaurant follow a Poisson distribution with a mean arrival rate of 16 customers per hour.What is the probability that in the next hour there will be exactly 12 arrivals?

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

If two events are mutually exclusive,the probability of both events occurring is simply the sum of the individual probabilities.

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 2 minutes for a particular customer to get a license renewal?