Exam 12: Introduction to Simulation Using Risk Solver Platform

What function should be used for generating random numbers from a normal distribution with mean $\mu$ and standard deviation $\sigma$ between the values of a and b only?

Which of the following do not help determine the magnitude of risk in a decision-making problem?

In general there are two primary issues involved in risk. What are these two issues?

A variable whose value cannot be predicted or set with certainty is a

Which of the following best describes a random variable?

The owner of Fix-a-dent Auto Repair wants to study the growth of his business using simulation. He is interested in simulating the number of damaged cars and the amount of damage to the cars each month. He currently repairs 100 cars per month and feels this can vary uniformly between a decrease of as much as 3% and an increase of up to 5% (average change of 1%) over the previous months. The dollar value of the damage to the cars is a normally distributed random variable with a mean of $3,000 and a standard deviation of $500. The average repair bill has been increasing steadily over the years and the owner expects the mean repair bill will increase by 1% per month. You have created the following spreadsheet to simulate the problem. -Using the information in Exhibit 12.1, what Risk Solver Platform (RSP) function should go in cell C8 and copied to cells C9:C19 to compute the average damage per car in the month?

The manager of a Washington, DC sightseeing tour company is concerned about overbooking for one of his bus tours. The bus has 15 seats but sometimes there are empty seats. His records show that about 20% of ticket holders do not show up for their tour. Tickets cost $10 and are non-refundable. If the manager overbooks the tour and more than 15 passengers show up, some of them will be bumped to a later tour. This bumping costs the company $25 in various expenses to keep the customer happy until the next tour. The manager wants to see what happens to profits if 18 reservations are accepted. -Using the information in Exhibit 12.4, what formula should go in cell C15 of the worksheet to determine the Marginal Profit?

What function should be used for generating random integer numbers between 2 and 8?

What method is used to generate observations from a distribution?

What gallery distribution should be used for generating the number of times "tails" come up over 15 flips of a "fair" coin?

An auto parts store wants to simulate its inventory system for engine oil. The company has collected data on the shipping time for oil and the daily demand for cases of oil. A case of oil generates a $10 profit. Customers can buy oil at any auto parts store so there are no backorders (the company loses the sale and profit). The company orders 30 cases whenever the inventory position falls below the reorder point of 15 cases. Orders are placed at the beginning of the day and delivered at the beginning of the day so the oil is available on the arrival day. An average service level of 99% is desired. The following spreadsheets have been developed for this problem. The company has simulated 2 weeks of operation for their inventory system. The current level of on-hand inventory is 25 units and no orders are pending. -Using the information in Exhibit 12.3, what Risk Solver Platform (RSP) function should be used for generating a random shipping time based on the Data spreadsheet distribution for shipping time?

The manager of a Washington, DC sightseeing tour company is concerned about overbooking for one of his bus tours. The bus has 15 seats but sometimes there are empty seats. His records show that about 20% of ticket holders do not show up for their tour. Tickets cost $10 and are non-refundable. If the manager overbooks the tour and more than 15 passengers show up, some of them will be bumped to a later tour. This bumping costs the company $25 in various expenses to keep the customer happy until the next tour. The manager wants to see what happens to profits if 18 reservations are accepted. -Using the information in Exhibit 12.4, what formula should go in cell C14 of the worksheet to determine the Cost of Bumping Passengers?

The owner of Sal's Italian Restaurant wants to study the growth of his business using simulation. He is interested in simulating the number of customers and the amount ordered by customers each month. He currently serves 1000 customers per month and feels this can vary uniformly between a decrease of as much as 5% and an increase of up to 9%. The bill for each customer is a normally distributed random variable with a mean of $20 and a standard deviation of $5. The average order has been increasing steadily over the years and the owner expects the mean order will increase by 2% per month. You have created the following spreadsheet to simulate the problem. -Sal, from Exhibit 12.5, has produced the following spreadsheet to compute confidence intervals on his income. What formula should go in cell B8 to compute the upper limit on a 95% confidence interval for the true population mean?

The owner of Sal's Italian Restaurant wants to study the growth of his business using simulation. He is interested in simulating the number of customers and the amount ordered by customers each month. He currently serves 1000 customers per month and feels this can vary uniformly between a decrease of as much as 5% and an increase of up to 9%. The bill for each customer is a normally distributed random variable with a mean of $20 and a standard deviation of $5. The average order has been increasing steadily over the years and the owner expects the mean order will increase by 2% per month. You have created the following spreadsheet to simulate the problem. -Sal, from Exhibit 12.5, has produced the following spreadsheet to compute confidence intervals on his income. What formula should go in cell B12 to compute the upper limit on a 95% confidence interval for the population proportion below 90%?

Jim Johnson operates a bus service to take college students to "The Big City" on Friday night and bring them back to school on Sunday night. The bus has 45 seats but sometimes there are empty seats. His records show that about 5% of ticket holders do not show up for their ride. Tickets cost $20 and are non-refundable. If Jim overbooks the bus and more than 45 passengers show up, some of them will be bumped and have to miss the trip. This bumping costs the company $40 because Jim has a double-your-money back policy for bumped passengers. Jim wants to see what happens to profits if 48 reservations are accepted. What formulas should go in cell C10 - C15 of the worksheet?

The owner of Fix-a-dent Auto Repair wants to study the growth of his business using simulation. He is interested in simulating the number of damaged cars and the amount of damage to the cars each month. He currently repairs 100 cars per month and feels this can vary uniformly between a decrease of as much as 3% and an increase of up to 5% (average change of 1%) over the previous months. The dollar value of the damage to the cars is a normally distributed random variable with a mean of $3,000 and a standard deviation of $500. The average repair bill has been increasing steadily over the years and the owner expects the mean repair bill will increase by 1% per month. You have created the following spreadsheet to simulate the problem. -Using the information in Exhibit 12.1, what formula should go cell G5 to calculate the 80^th percentile of the empirical distribution of income?

An auto parts store wants to simulate its inventory system for engine oil. The company has collected data on the shipping time for oil and the daily demand for cases of oil. A case of oil generates a $10 profit. Customers can buy oil at any auto parts store so there are no backorders (the company loses the sale and profit). The company orders 30 cases whenever the inventory position falls below the reorder point of 15 cases. Orders are placed at the beginning of the day and delivered at the beginning of the day so the oil is available on the arrival day. An average service level of 99% is desired. The following spreadsheets have been developed for this problem. The company has simulated 2 weeks of operation for their inventory system. The current level of on-hand inventory is 25 units and no orders are pending. -Using the information in Exhibit 12.3, what Risk Solver Platform (RSP) function should be used in cell I8 to determine the lead time for an order?

The owner of Fix-a-dent Auto Repair wants to study the growth of his business using simulation. He is interested in simulating the number of damaged cars and the amount of damage to the cars each month. He currently repairs 100 cars per month and feels the change in number of cars can vary uniformly between a decrease of as much as 3% and an increase of up to 5% (average change of 1%). The dollar value of the damage to the cars is a normally distributed random variable with a mean of $3,000 and a standard deviation of $500. The average repair bill has been increasing steadily over the years and the owner expects the mean repair bill will increase by 1% per month. A spreadsheet model to simulate the problem has been run 300 times. A part of the simulation statistics output from Risk Solver Platform (RSP)and a spreadsheet for computing confidence intervals follows. -Using the information in Exhibit 12.2, what formula should go in cell B12 of the Confidence Intervals spreadsheet to compute the upper limit on a 95% confidence interval for the population proportion below 90%?

An office supply store wants to simulate its inventory system for notebooks. The company has collected data on the shipping time and daily demand for notebooks. Each notebook generates a $2 profit. Customers can buy notebooks at any office supply store so there are no backorders (the company loses the sale and profit). The company orders 200 notebooks whenever the inventory position falls below the reorder point of 100 notebooks. Orders are placed at the beginning of the day and delivered at the beginning of the day so the notebooks are available on the arrival day. The average daily demand is 23.5 notebooks. An average service level of 99% is desired. There are currently 25 notebooks on hand and no orders are pending. The following spreadsheets have been developed for this problem. The company has simulated 1 month of operation for its inventory system. (HINT: This covers Rows 8 to 37 of the spreadsheet.) What formulas go in cells A1:J37 of the "Model" worksheet for this simulation?

Jim Johnson operates a bus service to take college students to "The Big City" on Friday night and bring them back to school on Sunday night. The bus has 45 seats but sometimes there are empty seats. His records show that about 5% of ticket holders do not show up for their ride. Tickets cost $20 and are non-refundable. If Jim overbooks the bus and more than 45 passengers show up, some of them will be bumped and have to miss the trip. This bumping costs the company $40 because Jim has a double-your-money back policy for bumped passengers. Jim plans to accept 48 reservations (overbook 3 seats). What is Jim Johnson's expected marginal profit?