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Quantitative Techniques
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1. A well-known stock expert conducts a popular training session in will he will charge participants $150 to attend. The cost of the meeting room, speaker fee, equipment, and advertise amounted to $3000. Assume it costs $25 per person for the organizer to provide the course materials (15 marks).
a. Write the expression for total cost for the training session. (3 marks)
Profit $150 per participant Cost= $3000 Cost $25 per student cost material
Let (x)= number of participants needed to attend
C(x) = 3000 + 25(x)
b. Write the expression for total revenue for the training session. (3 marks)
TR(x) = 150(x)
c. How many persons would have to attend for the company to break even? (4 marks)
C(x) = TR(x)3000 + 25x = 150x 3000 =150x 25x 3000 = 125x 3000/125 = x 24 = x
= 24 students need to attend in order to break-even.
d. If the organizers think, realistically, that 20 people will attend: (i) write the expression for total revenue. (2 marks)
Let x= number of participants attendingTR(x)= Profit (x)TR(20) = 150 (20) = 3,000
(ii) what price should be charged per person for the organization to break even? (3 marks)
Let p = price to change per participant
C(x) = TR(x)
3000 + 25(20) = p(20)3500 = 20p3500/20 = p175 = p
= Price to be charged per participant should be $175 in order to break-even.
2. A grocer solves a problem of how much pastry to order every day. His profit depends on a demand that can be low, moderate, or high. Values of the profit per day (in $) for these situations and for small, medium or large order are shown in Table 2.2 (15 marks). Table 2.2 Payoff Table for Order PlanningDecision(order)State of nature
lowmoderateHigh
Small 120150150
Medium 90250350
Large 60350600
Determine the size of the order that the manager should order according to:(a) Maximax criterion(5 marks)
Decision(order)State of natureRowMaximum
lowmoderateHigh
Small 120150150150
Medium 90250350350
Large 60350600600
= With the highest value of 600 of the last column, the best decision is to do the large order.
(b) Maximin criterion(5 marks)
Decision(order)State of natureRow Minimum
lowmoderateHigh
Small 120150150120
Medium 9025035090
Large 6035060060
= With the highest value of 120 of the last column, the best decision is to do the small order.
(c) Equally likely criterion(5 marks)
Decision(order)State of natureRow Mean
lowmoderateHigh
Small 120150150(120+150+150)/3 = 140
Medium 90250350(90+250+350)/3 = 230
Large 60350600(60+350+600)/3 = 336.67
= With the highest mean of 336.67, the best decision is to do the large order.
3. A payoff table is given as (13 marks)
State of Nature
Decisions1s2s3
d120 1816
d224 2512
d317 1819
a.What decision should be made by the optimistic decision maker? (3 marks)
State of NatureRow Maximum
Decisions1s2s3
d120 181620
d224 251225
d317 181919
= With the highest value of 25 of the last column, decision ( d2) should be selected.
b.What decision should be made by the conservative decision maker? (3 marks)
State of NatureRow Minimum
Decisions1s2s3
d120 181616
d224 251212
d317 181917
= With the highest value of 17 of the last column, decision (d3) should be selected.
c.What decision should be made under minimax regret? (7 marks)
State of Nature
Decisions1s2s3
d124- 20 = 4 25- 18= 719-16= 3
d224- 24 = 0 25-25 = 019- 12=7
d324- 17 = 7 25- 18= 719-19 = 0
State of NatureRowMaximum
Decisions1s2s3
d14737
d20077
d37707
= As the values of all the decisions have same maximum value, all 3 decisions can be selected.
4. Meng and Kee run a small electrical appliance shop and they must order table fans for the coming season. Orders for the fans must be placed in quantities of twenty (20). The cost per bicycle is $40 if they order 20, $37 if they order 40, $35 if they order 60, and $34 if they order 80. The fans will be sold for $70 each. Any fans left over at the end of the season can be sold (for certain) at $30 each. Meng and Kee estimate that the demand for fans this season will be 10, 30, 50, or 70 fans with probabilities of 0.2, 0.4, 0.3, and 0.1 respectively. (12 marks)
a. Construct the payoff table. (8 marks)
State of Nature
Decision10305070
200600600600
400141013201320
600195020502100
800252026002680
Probability0.20.40.30.1
b. Find the Expected Monetary value (EMV) (4 marks)
State of NatureEMV
Decision10305070
200600600600480
4001410132013201092
6001950205021001605
8002520260026802056
Probability0.20.40.30.1
EMV(20) = 0(0.2) + 600(0.4) + 600(0.3) + 600(0.1) = 480EMV(40) = 0(0.2) + 1410(0.4) + 1320(0.3) + 1320(0.1) = 1092EMV(60) = 0(0.2) + 1950(0.4) + 2050(0.3) + 2100(0.1) = 1605EMV(80) = 0(0.2) + 2520(0.4) + 2600(0.3) + 2680(0.1) = 2056
= Decision to order 80 has the highest expected monetary value (EMV), hence it is the best decision to take.
5. ABC company faces a payoff table as given below (15 marks):
DecisionState of nature
S1S2S3
D1250750500
D2300-2501200
D3500500600
a. If the probabilities of S1, S2 and S3 are 0.2, 0.5, and 0.3, respectively, then what choice should be made under expected monetary value (EMV)? (5 marks)
State of NatureEMV
DecisionS1S2S3
D1250750500575
D2300-2501200295
D3500500600530
Probability0.20.50.3
EMV(D1) = 250(0.2) + 750(0.5) + 500(0.3) = 575EMV(D2) = 300(0.2) + (-250)(0.5) + 1200(0.3) = 295EMV(D3) = 500(0.2) + 500(0.5) + 600(0.3) = 530
= Decision 1 has the highest expected monetary value (EMV), hence it is the best decision to take.
b. Find the Expected value with perfect information (EVWPI). (6 marks)
EVWPI = 500(0.2) + 750(0.5) + 1200(0.3) = 835
c. A market research company is trying to persuade ABC company to hire them to do market research so that the management of ABC co. can make better informed decision. So, What is the maximum amount that ABC company is willing to pay for the market information (hint: find the expected value of perfect information (EVPI))? (4 marks)
EVPI= EvWPI Maximum EMV = 835 575 = 260 = The maximum amount that ABC Company is willing to pay for the market information is RM 260.
6. An investor faces a payoff matrix table as shown below (15 marks).
Probability0.70.3
a. What decision should maximize the expected payoff (EMV)?(3 marks)Decision( Purchase )States of NatureEMV
Good Economic ConditionsPoor Economic Condition
Apartment Building50,00030,00050,000(0.7) + 30,000(0.3)= 44,000
Office Building100,00-40,000100,000(0.7) + (-40,000)(0.3)= 58,000
Warehouse30,00010,00030,000(0.7) + 10,000(0.3) = 24,000
Probability0.70.3-
= The maximum EMV is $58,000, therefore the decision is to purchase the office building.b. Determine the expected value with perfect information (EVWPI) and expected value of perfect information (EVPI)(5 marks) EVWPI = 100,000(0.7) + 30, 000 (0.3) = 70,000 + 9,000 = 79,000
EVPI = EVWPI Maximum EMV = 79,000 58,000 = 21,000
c. Calculate the expected opportunity loss (EOL).(7 marks)
Decision( Purchase )States of NatureEOL
Good Economic ConditionsPoor Economic Condition
Apartment Building50,000050,000(0.7) + 0(0.3)= 35,000
Office Building070,0000(0.7) + 70,000(0.3)= 21,000
Warehouse70,00020,00070,000(0.7) + 20,000(0.3) = 55,000
Probability0.70.3-
= Since the decision to purchase the office building has the minimum value of EOL that is $21,000 ( =EVPI), it is thus the best alternative.
7. A factory produces bowl and plate. The product resource requirement and unit profit are given below: (15 marks)
Resource Requirements
ProductLabor (Hr/unit)Clay (pound/unit)Profit ($/unit)
Bowl1440
Plate2350
Given 40 labor hours per day and 120lb of clay per day, answer the following questions:
a.Define the decision variables and write out the objective function and resource constraints. (8 marks)
X = Amount of bowls producedY= Amount of plates produced
Objective function : Max 40x + 50y
Constraintss.t x + 2y 40 4x + 3y 120 x, y 0
b.Use a graph to show the feasible region. (3 marks)
4x + 3y 120
When x=0,
4(0) + 3y =120 3y = 120 y = 120 3 y = 40(0,40)
When y=0 4x +3(0)=120 4x=120 x=120 4 x=30
(30,0)
x + 2y 40
When x=0,
0 + 2y=40 2y=40 y=40 2 y=20(0,20)
When y=0,
x+2(0)=40 x=40
(40,0)
c.What are the values of X and Y at the optimal solution? What is the optimal value of the objective function? (4 marks)
4x + 3y =120 (1) x + 2y = 40 - (2)
From (2) : x= 40 2y (3) Subsitute (3) into (1)
4(40-2y) + 3y =120160 8y + 3y =120 160 - 5y =120 -5y = 120-160 -5y = -40 y = (-40) (-5) y = 8When y=8,
x+2y =40x+2(8) =40 x+16=40 x =40-16 x =24
Corner pointsMax 40x +50y
(0,20)40(0) + 50(20) = 1000
(24,8)40(24) + 50(8) = 1360
(30,0)40( 30) + 50(0) = 1200
=The optimal value of the objective function is (24,8)