Exam 4: Introduction to Probability

The managers of a local golf course have recently conducted a study of the types of golf balls used by golfers based on handicap.A joint frequency table for the 100 golfers covered in the survey is shown below: If a player comes to the course using a Nike golf ball,the probability that he or she has a handicap of at least 10 is:

Assume P(A)= 0.6,P(B)= 0.7,and P(A andB)= 0.42,which means that events A and B are independent of each other.

The Crystal Window Company makes windows at three locations: Reno,Las Vegas,and Boise.Some windows made by the company contain a visible defect and must be replaced.Each defect costs the company $45.00.The Reno plant makes 40 percent of all windows while the Las Vegas and Boise plants split the remaining production evenly.A recent quality study shows that 8 percent of the Reno windows contain a defect,11 percent of the Las Vegas windows contain a defect,while 4 percent of the windows made in Boise have a defect.Once the windows are made,they are shipped to a central warehouse where they are commingled and the location where they were made is lost. Based on this information the probability that a defective window was made by the Boise plant is approximately 0.16.

A local FedEx/Kinkos has three black-and-white copy machines and two color copiers.Based on historical data,the chances that each black-and-white copier will be down for repairs is 0.10.The color copiers are more of a problem and are down 20% of the time each. Based on this information,what is the probability that if a customer needs a color copy,both color machines will be down for repairs?

The results of a census of 2,500 employees of a mid-sized company with 401(k)retirement accounts are as follows: Suppose researchers are going to sample employees from the company for further study. Compute the probability that a randomly selected employee will be a female with an account balance between $50,000 and $99,999.

What method of probability assessment would most likely be used to assess the probability that a major earthquake will occur in California in the next three years?

If a manager were interested in assessing the probability that a new product will be successful in a New Jersey market area,she would most likely use relative frequency of occurrence as the method for assessing the probability.

It is correct to say that subjective probability assessments are neither right nor wrong,but are merely reflections of the state of mind of the individual making the probability assessment.

In a survey,respondents were asked to indicate their favorite brand of cereal (Post or Kellogg's).They were allowed only one choice.What is the probability concept that implies it is not possible for a single respondent to state both Post and Kellogg's to be the favorite cereal?

Drake Marketing and Promotions has randomly surveyed 200 men who watch professional sports.The men were separated according to their educational level (college degree or not)and whether they preferred the NBA or the National Football League (NFL).The results of the survey are shown: What is the probability that a randomly selected survey participant has a college degree and prefers the NBA?

A car salesman has noted that the probability that the dealership sells a car on a Saturday morning is .30.Then the probability of the dealership not selling a car on Saturday morning is .70.

Three events occur with probabilities P(E₁)= 0.35,P(E₂)= 0.15,P(E₃)= 0.40.If the event B occurs,the probability becomes P(E₁|B)= 0.25,P(B)= 0.30. Assume that E₁,E₂,and E₃ are independent events.Calculate P(E₁ and E₂ and E₃).

The Crystal Window Company makes windows at three locations: Reno,Las Vegas,and Boise.Some windows made by the company contain a visible defect and must be replaced.Each defect costs the company $45.00.The Reno plant makes 40 percent of all windows while the Las Vegas and Boise plants split the remaining production evenly.A recent quality study shows that 8 percent of the Reno windows contain a defect,11 percent of the Las Vegas windows contain a defect,while 4 percent of the windows made in Boise have a defect.Once the windows are made,they are shipped to a central warehouse where they are commingled and the location where they were made is lost. Based on this information,the percentage of the defective cost that should be allocated to the Reno plant is approximately 42 percent.

Hubble Construction Company has submitted a bid on a state government project that is to be funded by the federal government's stimulus money in Arizona.The price of the bid was predetermined in the bid specifications.The contract is to be awarded on the basis of a blind drawing from those who have bid.Five other companies have also submitted bids. Suppose that there are two contracts to be awarded by a blind draw.What is the probability of Hubble winning both contracts? Assume sampling with replacement.

A manufacturing company makes three types of products.Each time it makes a product,the item can be either good or defective and it can be either customized or standard.The events consisting of customized and defective would be considered mutually exclusive since they apply to different attributes of the product.

During the past week,of the 250 customers at the Dairy Queen who ordered a Blizzard,50 ordered strawberry.This means that of the next five Blizzard customers,exactly one will order strawberry.

Suppose a coin is flipped twice.The event of getting heads on the first toss and the event of getting heads on the second toss could be said to be mutually exclusive.

Two football teams play in the Super Bowl.The event of team A winning and the event of team B winning can be said to be mutually exclusive.

The Baker Oil and Gas Company has four retail locations,code-named A,B,C,and D.The following table illustrates the percentage of total company sales at each store and also the percentage of customers at that store who make purchases with debit cards: Based on this information,given that a customer has used a debit card to make the purchase,the sale was most likely made at store D.

When customers come to a bank,there are three primary locations they may select to go to: teller,loan officer,or escrow department.Based on past experience,the following probability distribution applies: Seventy percent of customers are males.The probability that the next two customers to enter the bank are males and go to the Loan Officer is 0.42.