Exam 4: Introduction to Probability

An event is:

A dam on a river that holds back a water reservoir begins to leak.Engineers say that there is a 10 percent chance of the dam breaking if repairs are not made.This is an example of classical probability.

Suppose a single die (a 6-sided cube with sides numbered 1 through 6)is rolled once.The event of interest is defined as rolling an even number.This can be said to be an elementary event.

The following probability distribution was subjectively assessed for the number of sales a salesperson would make if he or she made five sales calls in one day. Given this distribution,the probability that the number of sales is less than 2 is 0.15.

Suppose a player is dealt 2 cards from a standard deck of 52 playing cards.To determine the probability of having a blackjack would involve classical probability.

Micron Technology has sales offices located in four cities: Dallas,Seattle,Boston,and Los Angeles.An analysis of the company's accounts receivables reveals the number of overdue invoices by days,as shown here. Assume the invoices are stored and managed from a central database. What is the probability that a randomly selected invoice from the database is from the Boston sales office?

The Jack In The Box franchise in Bangor,Maine,has determined that the chance a customer will order a soft drink is 0.90.The probability that a customer will order a hamburger is 0.60.The probability that a customer will order french fries is 0.50. The restaurant has also determined that if a customer orders a hamburger,the probability the customer will also order fries is 0.80.Determine the probability that the order will include a hamburger and fries.

The URS construction company has submitted two bids,one to build a large hotel in London and the other to build a commercial office building in New York City.The company believes it has a 40% chance of winning the hotel bid and a 25% chance of winning the office building bid.The company also believes that winning the hotel bid is independent of winning the office building bid. What is the probability the company will win at least one contract?

A study was recently done in which 500 people were asked to indicate their preferences for one of three products.The following table shows the breakdown of the responses by gender of the respondents. If the people conducting the study wish to assess the probability that product A will be preferred by members of the target population,the method of assessment to be used would most likely be:

Men have a reputation for not wanting to ask for directions.A Harris study conducted for Lincoln Mercury indicated that 42% of men and 61% of women would stop and ask for directions.The U.S.Census Bureau's 2012 population estimate was that for individuals 18 or over,48.2% were men and 51.8% were women.This exercise addresses this age group. Calculate the probability that the driver stops to ask for directions.

Suppose a quality manager for Dell Computers has collected the following data on the quality status of disk drives by supplier.She inspected a total of 700 disk drives. What is the probability of a defective disk drive being received by the computer company?

When a customer enters a store there are three outcomes that can occur: buy nothing,buy a small amount,or buy a large amount.In this situation,if a customer buys a large amount,he or she cannot also buy a small amount or buy nothing.Thus the events are:

Until the summer of 2006,the real estate market in Fresno,California,had been booming,with prices skyrocketing.Recently,a study showed the sales patterns in Fresno for single-family homes.One chart presented in the commission's report is reproduced here.It shows the number of homes sold by price range and number of days the home was on the market. Using the relative frequency approach to probability assessment,what is the probability that a house will be on the market more than 7 days?

An inventory of appliances contains four white washers and one black washer.If a customer selects one at random,what is the probability that the black washer will be selected?

Assume P(A)= 0.4 and P(B)= 0.2 and P(A andB)= 0.1,then the probability of P(A orB)= 0.7.

List three methods of assessing probabilities and indicate which is least likely to be used in business decision making.

Ponderosa Paint and Glass carries three brands of paint.A customer wants to buy another gallon of paint to match paint she purchased at the store previously.She can't recall the brand name and does not wish to return home to find the old can of paint.So she selects two of the three brands of paint at random and buys them. What is the probability that she matched the paint brand?

When a construction company bids on a contract,the events will be win or lose.The closer the probability is to 0.50,the greater the uncertainty about whether the company will win or lose the bid.

If a single die is rolled (a cube where the sides are numbered 1 through 6),the probability of rolling at least a 3 is 0.33.

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.Thus,the probability that the next customer to enter the bank is a male who goes to the teller is 1.30.