Comm 190

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Simon Fraser University *

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190

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Communications

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Jan 9, 2024

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Studocu is not sponsored or endorsed by any college or university COMM 190 Midterm - The time limit is 1.5 hrs. The Data required to solve this paper is already Introduction To Quantitative Decision Making (The University of British Columbia) Studocu is not sponsored or endorsed by any college or university COMM 190 Midterm - The time limit is 1.5 hrs. The Data required to solve this paper is already Introduction To Quantitative Decision Making (The University of British Columbia) Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 1/29 2022W1 COMM 190 Midterm Results Score for this quiz: 56 out of 81 Submitted Oct 20 at 9:02p.m. This attempt took 90 minutes. 0.5 / 0.5 pts Question 1 Academic pledge. Please read carefully. I hereby agree that I will not give or receive unauthorized help on this exam, that all work will be my own, and that I will abide by the rules outlined below. I am not allowed to: Communicate in any way with other students until after the exam is over. Post questions, content, screenshots, ideas, etc ., from the exam on any public or private sites, or otherwise share such material. I understand that failure to adhere to this pledge may result in severe disciplinary action. I agree and I understand Correct! Correct! Please periodically check the bottom of the exam to make sure your answers are saving. If everything is working great: "Quiz saved at [local time] "Not Saved" — THIS IS OKAY (KNOWN BUG IN CANVAS) If your internet is not working properly: Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 2/29 1 / 1 pts Question 2 Colourful Constraints An LP, shown below, has five constraints (in different colours) plus two non-negativity constraints. Use this diagram to answer this and the following True/False questions. It is possible that some of the constraints are equality ("=" sign) constraints. True False Correct! Correct! "Saving..." This indicates that there may be a problem with your Wi-Fi. Please try to reconnect by turning Wi-Fi off and back on. Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 3/29 1 / 1 pts Question 3 Point E violates the two non-negativity constraints but satisfies all of the other constraints. True False Correct! Correct! 1 / 1 pts Question 4 Points E , F , and G violate the non-negativity of y. True Correct! Correct! False 1 / 1 pts Question 5 Point C would be feasible if the Green constraint were removed. True Correct! Correct! False 1 / 1 pts Question 6 Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 4/29 Points A and C violate the same constraints. True False Correct! Correct! 1 / 1 pts Question 7 Still Constrained Now consider a different LP with three constraints (in different colours) plus two non-negativity constraints. The constraints are all inequality constraints (≤ or ≥). Use this diagram to answer this and the following True/False questions. If point B is optimal, point C cannot also be optimal. True Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 5/29 False Correct! Correct! 1 / 1 pts Question 8 If points B and C are both feasible solutions, then point D must be feasible as well. True False Correct! Correct! 0 / 1 pts Question 9 If point C is a feasible solution, then point A could be the unique optimal solution. True ou Answered ou Answered False orrect Answer orrect Answer 0 / 3 pts Question 10 Vegetable Farm — Arugula and Bok Choy Consider a vegetable Farm problem: Each square metre of A rugula uses 14 hours of weeding and 6 hours of harvesting; each square metre of B ok Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 6/29 Choy uses 6 hours of weeding and 4 hours of harvesting. (Arugula is a leafy green vegetable; Bok Choy is related to cabbage.) You have 140 hours of weeding and 80 hours of harvesting available. Revenue is $24/Arugula square metre and $18/Bok Choy square metre, and you want to maximize revenue. Set up and solve this LP by hand. Answer this question and then continue with the True/False questions that also pertain to this model. What is the revenue at the optimal solution? Just type the value, e.g., 400. Do not include a dollar sign, units, or other characters. Do not include decimals. 346 ou Answered ou Answered orrect Answers orrect Answers 360 (with margin: 0) 0 / 1 pts Question 11 One of the non-negativity constraints is binding. True orrect Answer orrect Answer False ou Answered ou Answered 1 / 1 pts Question 12 There are two binding constraints at the optimal solution. True Correct! Correct! Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 7/29 False 1 / 1 pts Question 13 Slope of weeding <= Slope of the isoprofit line <= Slope of harvesting True False Correct! Correct! 1 / 1 pts Question 14 If the farm had an unlimited amount of hours of weeding and hours of harvesting this problem would be infeasible. True False Correct! Correct! 2 / 2 pts Question 15 Suppose the revenue per unit changes. For this question only, revenue is now $11.3/Arugula square metre and $6/Bok Choy square metre. What is the allowable increase of the objective coefficient for Arugula? Just type the value. Do not include a dollar sign, units, or other characters. Report to one decimal place (if necessary). Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 8/29 2.7 Correct! Correct! 2.7 orrect Answer orrect Answer 3 / 3 pts Question 16 Vegetable Farm — Minimizing Cost Now consider a version of this LP where the farm wants to minimize costs. Arugula costs $5.18/square metre to farm and Bok Choy costs $2.62/square metre. The weeding and harvesting constraints are the same as above. Additionally, the farm wants to produce at least 3 of each square metre. Answer this question and then continue with the True/False questions (they also pertain to this minimizing cost model). What is the cost at the optimal solution? Report your answer in dollars without a dollar sign or other characters, to 2 decimal places (if necessary). 23.4 Correct! Correct! 23.4 orrect Answer orrect Answer 1 / 1 pts Question 17 This model has 6 constraints in total. True Correct! Correct! False Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 9/29 1 / 1 pts Question 18 This model has an unbounded feasible region. True False Correct! Correct! 1 / 1 pts Question 19 If the cost per square metre of Arugula increased by $3, the optimal solution would change. True False Correct! Correct! 2 / 2 pts Question 20 Still continuing with the minimizing cost model, what is the shadow price of harvesting? Report your answer, to 2 decimal places (if necessary). 0 Correct! Correct! orrect Answers orrect Answers 0 (with margin: 0) Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 10/29 2 / 2 pts Question 21 Brain Teaser What is the optimal solution to the following LP: max j – k s.t. j ≤ 1 k ≤ 1 j, k ≥ 0 (select the best answer) (0, 1) (1, 1) (0, 0) (1, 0) Correct! Correct! (1, 0) and (0, 1) Please periodically check the bottom of the exam to make sure your answers are saving. If everything is working great: "Quiz saved at [local time] "Not Saved" — THIS IS OKAY (KNOWN BUG IN CANVAS) If your internet is not working properly: "Saving..." This indicates that there may be a problem with your Wi-Fi. Please try to reconnect by turning Wi-Fi off and back on. Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 11/29 10.5 / 12 pts Question 22 Recycling Company Each week your recycling company must ship at least a certain number of truckloads of plastic waste from several cities to several processing plants in other cities. This week they have determined the total cost is $41,050. The following LP is solved to optimality, and the resulting sensitivity report is produced. Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 12/29 Answer the following questions using the information provided: a. How many more truckloads could Kelowna receive compared to what they are receiving? 20 Just type a number. Do not include other characters or decimals. b. What is the total cost to ship from North Van to Princeton? 6000 Just type the number. Do not include a dollar sign, units, or other characters. Do not include decimals. c. How many of the non-negativity constraints are binding? 5 Type an integer. d. What is the formula in H24? =E14 Type the formula exactly as it should appear, starting with = e. What is the formula in F25? Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 13/29 Answer 1: Answer 2: =E15 Type the formula exactly as it should appear, starting with = For the next three questions, if you cannot answer based on the information given in the sensitivity report, type X. f. Suppose the cost to ship from Vancouver to Kelowna increased by 10. What would the total cost become? In other words, what value would be in the green cell? 41550 Just type the number. Do not include a dollar sign, units, or other characters. Do not include decimals. g. Suppose instead that the capacity in Princeton decreased by 12. What would the total cost be? 41590 Just type the number. Do not include a dollar sign, units, or other characters. Do not include decimals. h. Now suppose instead that the amounts Vancouver and Richmond must ship each increased by 18 truckloads. What would the total cost be? 48520 Just type the number. Do not include a dollar sign, units, or other characters. Do not include decimals. 20 Correct! Correct! 20.0 orrect Answer orrect Answer 6000 Correct! Correct! 6000.00 orrect Answer orrect Answer $6000 orrect Answer orrect Answer Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 14/29 Answer 3: Answer 4: Answer 5: Answer 6: Answer 7: $6000.00 orrect Answer orrect Answer 6,000 orrect Answer orrect Answer 6,000.00 orrect Answer orrect Answer 5 Correct! Correct! five orrect Answer orrect Answer =E14 Correct! Correct! E14 orrect Answer orrect Answer =E15 Correct! Correct! E15 orrect Answer orrect Answer 41550 Correct! Correct! 41550.00 orrect Answer orrect Answer $41550 orrect Answer orrect Answer $41550.00 orrect Answer orrect Answer 41,550 orrect Answer orrect Answer 41,550.00 orrect Answer orrect Answer 41590 Correct! Correct! 41590.00 orrect Answer orrect Answer $41590 orrect Answer orrect Answer Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 15/29 Answer 8: $41590.00 orrect Answer orrect Answer 41,590 orrect Answer orrect Answer 41,590.00 orrect Answer orrect Answer 48520 ou Answered ou Answered X orrect Answer orrect Answer x orrect Answer orrect Answer 2 / 2 pts Question 23 Continue with the Recycling model for this question and the following true/false questions. The sum of the "Must Ship" values is less than the sum of the "Capacity" values. Which of the following statements correctly explains why it is this way? (select the best answer) None of the other answers is correct. The number of truckloads that will end up being received is less than the amount that those three cities are able to handle. Correct! Correct! Recycling processing plants could always handle more truckloads. Supply must not be less than demand. That is a mistake. The model should be infeasible. Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 16/29 1 / 1 pts Question 24 All three of the capacity constraints at the processing plants are binding. True False Correct! Correct! 1 / 1 pts Question 25 All four of the constraints about how many truckloads must be shipped from the "From" locations are binding. True Correct! Correct! False 0 / 1 pts Question 26 If the capacities (at Surrey, Princeton, and Kelowna) were infinite, this problem would not have an optimal solution because it would be unbounded. True ou Answered ou Answered False orrect Answer orrect Answer Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 17/29 1.5 / 3 pts Question 27 A different version of the Recycling LP was solved, producing the following sensitivity report. Use this sensitivity report to answer these questions and the following multiple choice questions. (And as always, consider each question about the sensitivity report in isolation.) a. What is the total cost at the optimal solution? 40350 Just type the number. Do not include a dollar sign, units, or other characters. Do not include decimals. b. In total, how many constraints are binding? Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 18/29 Answer 1: Answer 2: 6 Type an integer. 40350 Correct! Correct! 40350.00 orrect Answer orrect Answer $40350 orrect Answer orrect Answer $40350.00 orrect Answer orrect Answer 40,350 orrect Answer orrect Answer 40,350.00 orrect Answer orrect Answer 6 ou Answered ou Answered 12 orrect Answer orrect Answer 12.0 orrect Answer orrect Answer 2 / 2 pts Question 28 What will happen if the RHS of the North Van constraint is decreased by 20? (select the best answer) The target cell will decrease by at least $1950. Correct! Correct! The target cell will decrease by $1950. None of the other answers is correct. Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 19/29 The target cell will decrease by $3900. The target cell will decrease by at least $3900. 0 / 2 pts Question 29 What will happen if the RHS of the Kelowna constraint decreases 21? None of the other answers is correct. orrect Answer orrect Answer The optimal solution will not change but the target cell will change. Both the optimal solution and the target cell will change. ou Answered ou Answered The optimal solution will not change and the target cell will not change. The optimal solution will change, but the target cell will not change. 2 / 2 pts Question 30 What will most likely happen if the cost of shipping from Vancouver to Kelowna increases by $12? (select the best answer) Both the optimal solution and the target cell will change. Correct! Correct! The optimal solution will not change and the target cell will not change. The optimal solution will change, but the target cell will not change. None of the other answers is correct. Downloaded by Jake Paul (hifat91162@locawin.com)
11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 20/29 The optimal solution will not change but the target cell will change. 0 / 3 pts Question 31 Miscellaneous Questions Suppose we wish to create a constraint that says there must be at most 3 times more S UVs than T railers. Which of the following would be correct ways to express this constraint in an LP? (select all correct answers) 3S ≤ T ou Answered ou Answered –S + 3T ≥ 0 orrect Answer orrect Answer S/T ≤ 3 –3S + T ≤ 0 S ≤ 3T orrect Answer orrect Answer 3S – T ≤ 0 ou Answered ou Answered S + 3T ≤ 0 2 / 2 pts Question 32 Consider the following set of constraints, correctly graphed below: x + 2y ≥ 10 5x + y ≤ 30 Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 21/29 x + 10y ≥ 40 Which of the points are in the feasible region? (select all correct choices) B C D There is no feasible region. E F G A 0 / 3 pts Question 33 Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 22/29 This question and the following True/False questions also pertain to the above graph of the three constraints. Assume, as always, that there are non-negativity constraints as well. What could we say about the LP if all three constraints had ≥ signs? (select all correct answers) There can be no optimal solution because the problem is certainly unbounded. The intersection just above D must be the optimal solution. ou Answered ou Answered The feasible region would be unbounded. Correct! Correct! Both of the non-negativity constraints could be binding simultaneously. The LP would be infeasble. One of the non-negativity constraints could be binding. orrect Answer orrect Answer Please periodically check the bottom of the exam to make sure your answers are saving. If everything is working great: "Quiz saved at [local time] "Not Saved" — THIS IS OKAY (KNOWN BUG IN CANVAS) If your internet is not working properly: "Saving..." This indicates that there may be a problem with your Wi-Fi. Please try to reconnect by turning Wi-Fi off and back on. Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 23/29 1 / 1 pts Question 34 The region containing point F is unbounded. True False Correct! Correct! 1 / 1 pts Question 35 The region containing point G is unbounded. True False Correct! Correct! 1 / 1 pts Question 36 If all three constraints had ≤ signs then the feasible region would have 5 corner points. True Correct! Correct! False 1.5 / 3 pts Question 37 Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 24/29 Consider this system of two equations: 7x + 12y = 97 (raking) 11x + 8y = 109 (baling) To solve this system by elimination, which of the following are correct first steps? (select all correct answers) Multiply baling by 1.5 orrect Answer orrect Answer Multiply raking by 12/8 Multiply raking by 7 and baling by 11. Multiply baling by 11/7 Multiply raking by 11/7 Correct! Correct! 3 / 3 pts Question 38 What is true about blending constraints? (select all correct answers) We generally set them up in Excel with some variables in the RHS. Correct! Correct! Excel rearranges them so that all the variables are on the left. Correct! Correct! The allowable increase and decrease of the RHS will be expressed as a percent. Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 25/29 They cannot have a negative shadow price because they involve percentages, which are always non-negative. They must be written so that they don't involve variables in both the numerator and the denominator. Correct! Correct! The sensitivity report will show LHS equal to RHS if the constraint is binding. Original Score: 1 / 3 pts Regraded Score: 1.5 / 3 pts Question 39 This question has been regraded. Consider a two-variable LP. When modelled in Excel and solved, the solver says "The objective cell values do not converge." Which statement(s) could be true about this LP? (select all correct answers) The feasible region is unbounded. Correct! Correct! The objective function begins with "min". orrect Answer orrect Answer The feasible region is a triangle. The feasible region is a line. There is no feasible region. The feasible region is a point. Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 26/29 0 / 3 pts Question 40 Consider a two-variable LP. When modelled in Excel and solved, the solver says "Solver found a solution. All constraints and optimality conditions are satisfied." This LP has five regular constraints plus the two non-negativity constraints. All regular constraints are inequalities (≤ or ≥) except for one, which is an equality constraint (=). Which statement(s) could be true about the feasible region? (select all correct answers) The feasible region is a five-sided shape. The feasible region is a seven-sided shape. ou Answered ou Answered The feasible region is a triangle. The feasible region is a line segment. orrect Answer orrect Answer There is no feasible region. The feasible region is a point. orrect Answer orrect Answer 2 / 4 pts Question 41 University Counselling Services University Counselling Services (UCS) provides mental health services to students. They require a certain number of counsellors to work during each 4-hour period from 08:00 (am) until 00:00 (midnight). The following LP is solved to optimality. Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 27/29 Answer 1: Answer the following questions using the information provided: a. What is the value in cell H5? 12 Just type a value as Excel would display it using the default formatting. b. What is the value in cell H7? 12 Just type a value as Excel would display it using the default formatting. c. How many of the Demand constraints are non-binding? 1 Just type the number with no other characters. d. What type of LP is this? Scheduling Type a one-word answer, making sure you spell it correctly. A couple variations on the word will be accepted. 12 ou Answered ou Answered Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 28/29 Answer 2: Answer 3: Answer 4: 1 orrect Answer orrect Answer 1.0 orrect Answer orrect Answer 1.00 orrect Answer orrect Answer 12 ou Answered ou Answered 0.5 orrect Answer orrect Answer .5 orrect Answer orrect Answer 0.50 orrect Answer orrect Answer .50 orrect Answer orrect Answer 1 Correct! Correct! scheduling Correct! Correct! schedule orrect Answer orrect Answer scheduled orrect Answer orrect Answer 0.5 / 0.5 pts Question 42 What is Greg's favourite Excel function? (select the best answer) SUMPRODUCT Correct! Correct! Dumb product! Downloaded by Jake Paul (hifat91162@locawin.com)
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11/10/22, 8:38 PM https://canvas.ubc.ca/courses/101551/quizzes/562169/history?version=2 29/29 Yum product? drum product crumb PRODUCT Quiz Score: 56 out of 81 Downloaded by Jake Paul (hifat91162@locawin.com)
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