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.If a sales dollar is recorded as a boat accessory,the probability that the sale was made at the Portland store is:

Based on weather data collected in Racine,Wisconsin,on Christmas Day,the weather had the following distribution: Supposing next Christmas is dry,determine the probability that it will also be cloudy.

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,if a defective window is discovered,it was most likely made by the Las Vegas plant.

Cross County Bicycles makes two mountain bike models that each come in three colors.The following table shows the production volumes for last week: What is the probability that the product manufactured is a YZ-99?

A distributor of outdoor yard lights has four suppliers.This past season she purchased 40% of the lights from Franklin Lighting,30% from Wilson & Sons,20% from Evergreen Supply,and the rest from A.L.Scott.In prior years,3% of Franklin's lights were defective,6% of the Wilson lights were defective,2% of Evergreen's were defective,and 8% of the Scott lights were defective.When the lights arrive at the distributor,she puts them in inventory without identifying the supplier.Suppose that a defective light string has been pulled from inventory;what is the probability that it was supplied by Franklin Lighting?

Cross County Bicycles makes two mountain bike models that each come in three colors.The following table shows the production volumes for last week: What is the joint probability that a product manufactured is a YZ-99 and brown?

Students who live on campus and purchase a meal plan are randomly assigned to one of three dining halls: the Commons,Northeast,and Frazier.What is the probability that the next student to purchase a meal plan will be assigned to the Commons?

Based on weather data collected in Racine,Wisconsin,on Christmas Day,the weather had the following distribution: Based on the data,what is the probability that next Christmas will be rainy or cloudy and dry?

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. Based on the relative frequency assessment method,what is the probability that a randomly selected employee will be a female?

What method of probability assessment would most likely be used to assess the probability that a customer will return a purchase for a refund?

One of the difficulties in using the relative frequency of occurrence method for assessing probabilities in business situations is getting a large enough set of examples that match the one in question.

If two events are independent,then

A special roulette wheel,which has an equal number of red and black spots,has come up red four times in a row.Assuming that the roulette wheel is fair,what concept allows a player to know that the probability the next spin of the wheel will come up black is 0.5?

Parts and Materials for the skis made by the Downhill Adventures Company are supplied by two suppliers.Supplier A's materials make up 30% of what is used,with supplier B providing the rest.Past records indicate that 15% of supplier A's materials are defective and 10% of B's are defective.Since it is impossible to tell which supplier the materials came from once they are in inventory,the manager wants to know which supplier most likely supplied the defective materials the foreman has brought to his attention.Provide the manager this information.

Of the last 100 customers entering a computer shop,25 have purchased a computer.If the classical probability assessment for computing probability is used,the probability that the next customer will purchase a computer 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. A randomly chosen driver gets lost on a road trip.Determine the probability that the driver is a woman and stops to ask for directions.

Classical probability assessment is likely to be the most common method of probability assessment used in business decision making.

If two events are mutually exclusive,it is possible for them to also be independent of each other.

Cross County Bicycles makes two mountain bike models that each come in three colors.The following table shows the production volumes for last week: Based on the relative frequency assessment method,what is the probability that a manufactured item is brown?

Explain why it is possible for two managers to assess different values for the probability that a supplier will fail to deliver a shipment on time.