Exam 4: Introduction to Probability

Harrison Water Sports has three retail outlets: Seattle,Portland,and Phoenix.The Seattle store does 50 percent of the total sales in a year,while the Portland store does 35 percent of the total sales.Further analysis indicates that of the sales in Seattle,20 percent are in boat accessories.The percentage of boat accessories at the Portland store is 30 and the percentage at the Phoenix store is 25.Overall,the probability that a sale by Harrison Water Sports will be for a boat accessory is:

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.Calculate P(E₁ and B).

Suppose 10 students are enrolled in a class and the probability of at least 8 showing up on a given day is 90 percent.Then the probability of 7 or fewer showing that day is 10 percent.

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 over 90 days old and from the Seattle office?

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 between 30 and 90 days overdue?

If the probability of one event occurring is .40 and the probability of a second event occurring is 0.60,then the probability that both events will occur must be 1.0 since that is the maximum value a probability can be.

If you were planning to take a small group out to dinner on a Thursday evening and you were considering whether to call ahead for a reservation,the method of probability assessment you would most likely use to assess the chances of being able to get in for dinner without having a reservation would be subjective assessment.

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 three consecutive customers all go to a teller is approximately 0.22.

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: Based on these data,the probability of someone using a Strata ball and having a handicap under 2 is:

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. Given that a driver stops to ask for directions,determine the probability that the driver was a man.

When the salesperson makes a sale,there are three possible sales levels: large,medium,and small.The probability of a large sale is 0.20 and the chance of a medium sale is 0.60.Thus,when a sale is made,the chance of it being a small sale is 0.20.

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 more than 2 is 0.80.

Sometime it is necessary to assign probabilities based on a person's belief that an outcome will occur.

A used car lot has 15 cars.Five of these cars were manufactured in the United States and the others were made in other countries.If one car is purchased at random from this car lot,the probability that it is a U.S.car is 0.33.

The method of probability assessment that is least likely to be used by business decision makers is:

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 defect given that company B supplied the disk drive?

The method of probability assessment that relies on an examination of historical data from similar situations is:

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: Based on these data,the probability that a player will use a Strata golf ball is:

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. Suppose one person is randomly chosen.Based on this data,what is the probability that the person chosen is a female who prefers product C?

Assume that a standard deck of 52 playing cards is randomly shuffled and the first 2 cards are dealt to you.What is the probability that you have a blackjack? A blackjack is where one card is an ace and the other card is worth 10 points.The 10-point cards are kings,queens,jacks and 10's.