Doulton - BDM Flashcards
Probability:
P(A)
The probability of event A
Probability:
P(A’)
The probability of everything which is not A
Probability:
P(A and B)
or P(AB)
The intersection/joint probability:
The probability of event A and event B occurring at the same time
Equation Given
Probability:
P(A or B)
The union:
The probability of either event A or event B occurring
Equation given
Probability:
P(A / B)
Conditional Probability:
The probability of event A, given that B already occurred
Equation given
Mutually Exclusive =
When two event cannot occur at the same time. (Not independent)
Ex: You cannot roll and 4 & 5 on a dice at the same time./
Independence
Two events, A and B, are independent if the fact that A occurs DOESN’T affect the probability of B occurring
P(A and B)
P(A/B)
Rule of Conditional Probability
P(A/B) = P(A and B)
__________
P(B)
Bayes Theorem =
Describes the probability of an event, based on prior knowledge of conditions that might be related to the event .
Ex: performing well in class is related to having attended class (Bayes theorem involves assessing with more information)
Equation Given
Binomial Distribution
The binomial distribution is a discrete distribution
It is used when we do the same thing ‘n’ times, and each time there is the same probability of success
Poisson distribution
The Poisson distribution models the number of arrivals/occurences (X) which happens over a fixed interval (ex: hour) when you know the average number of arrivals (lagrange)
Decision Making:
Decision Making under Certainty =
When the decision maker knows the payoff of each option/choice and can choose the option that maximizes their utility
Ex: Choosing to buy the same product online vs. in the store - You would choose the lowest price option.
Decision Making:
Decision Making under Uncertainty =
When there are multiple outcomes for each choice, but the decision maker doesn’t know the probability of each outcome.
Ex: Which job makes you happiest in life
Decision Making:
Decision Making under Risk =
When there are multiple outcomes for each choice, but the decision makers knows the probability of each outcome
- Most of our problems
Ex: Playing a card game or the lottery, the odds of winning can be calculated.
Decision Making under Uncertainty:
MaxiMax (optimistic)
The option with the greatest potential payoff
Decision Making under Uncertainty:
MaxiMin (pessimistic)
The option with the highest WORST option
Decision Making under Uncertainty:
Weighted Average
Given probabilities are assigned to each outcome
(basically makes it Decision making under risk).
Choose the one which has the highest expected payoff (or lowest expected cost)
Equally Likely (Laplace)
Simular to the Weighted Average, however equal probabilities are used (the amount of all options to choose from)
MinMax Regret
The outcome with the minimum of all possible regrets
Use a table to calculate
Regret (opportunity loss) = Best pay off - payoff received
Find the Maximum regret for each alternative, and then choose the minimum from this quantities
Decision Trees =
Decision Trees model sequential events. It captures decisions to be made, probabilities for each event and the outcome of each set of decisions and events
They are draw from start to finish, but solved backwards
Decision Tree :
Square
Represents a decision
Decision Tree :
Circle
Represents a probability event
Decision Tree :
Triangle
The end of the set of events
EMV (Decision making under risk)
Expected Monetary Value :
= The expected value of the payoffs. No perfect information
Equation Given
EVxPI (Decision making under risk)
Expected Value with Perfect Information:
= The expected value if we had all the information before the decision had been made
Equation Given
EVPI (Decision making under risk)
Expected Value of Perfect information:
= sets the maximum we would be willing to pay for the perfect information
Equation Given
EVSI (Decision making under risk)
Expected Value of Sample information:
= expected value of sample information is the increased expected value resulting from having sample information. The value of the sample information is the difference of payoff you would get with the sample and without the sample
Expected Utility
The utility of each event added up
Risk Neutral =
A risk neutral person has NO preference between outcomes which have the same expected payoff. (As long as it gets you the same in the end)
Risk Adverse/Risk Avoider
A risk adverse person prefers certainty over risk. it is a CONCAVE function.
Ex: a Risk adverse person with a utility function of U(x) = (square root)x
Risk Loving/Seeeking
A risk loving/seeking person prefers the potential upside of risk of certainty. CONVEX function
Linear Programming =
The maximization or minimization of linear objective function subject to linear constraints using the algorithm of Simplex LP.
The solution is based on defining the 1) decision variables, 2) objective functions, 3) and constraints
Properties of Linear Programming
- One objective function
- One or more constraints
- Alternative courses of action (i.e. the decision variables can take on different numbers)
- Equations are linear - proportionality and divisibility
- Certainty (coefficients you are using are not going to change)
- Divisibility (solutions do not need to be whole numbers)
- Nonnegative variables (you can’t have a negative number of cups)
Components of Linear Programming Solution:
1. Decision Variables =
“Let X be …….”
What you control directly in the problem
Results of core decisions are constraints, and not decisions
Components of Linear Programming Solution:
2. Objective Function =
Profit, Revenue, or Cost
The value you are trying to minimize or maximize.
Must relate the decision variables to a single value.
Must be linear.
Components of Linear Programming Solution:
3. Constraints =
Constraints limit the objective function
Graphical Solutions for Linear Programming
Simple problems can be solved graphically (limited to two variables only) where the feasible region is found, and the objective function is pushed away from (0,0), if the maximization problem or the objective function is pushed towards (0,0) if a minimization problem.
Linear Programming Types of Problems:
Resource allocation Inventory Marketing Investment Transportation Problem Blending Problems
Linear Programming Types of Problems: Resource Allocation
You decide how much to make/produce of each item. The recipe is given
Linear Programming Types of Problems: Inventory
You must order or produce each period and you have the option of holding inventory until the next period. There may be reference to holding costs or the cost of producing or ordering the product changes period to period
Decision Variable:
Xi - the quantity of widgets to produce in period I
Ii - the quantity of widgets to hold in inventory at the end of month i
Objective Function:
min Cost = Production costs + Holding costs
S.t.:
Amount left over this period = Amount started with + in - out
Linear Programming Types of Problems: Marketing
You are deciding how many ads to run in each market or type
Linear Programming Types of Problems: Investment
Decision variables:
the number of shares/stocks to buy or the dollar amount to invest
Linear Programming Types of Problems: Transportation
Decision Variables:
Decide how much to ship along each route, typically xii variable
“Let Xii represent the amount shipped from location i to location j
Objective:
Usually minimize the cost of shipping
Constraints:
Supply: what leaves a supply node < what is available at the node
Demand: what arrives to a demand node > what is required at that node
Linear Programming Types of Problems: Blending Problems
Decision Variables:
the amount of each ingredient in each project
Let xij be the quantity of input i which goes into product j
Objective Function:
max Profit = Revenue from products - cost of inputs
Constraints
Common constraints include supply and demand and can be treated similarly as outlines in the transportation section.
Sensitivity Analysis
The Sensitivity Analysis gives us information on the impact of changing:
1) the coefficients of the objective function, and
2) the right hand side of the constraint.
Sensitivity Analysis
Analyzing the Variable Cells (in sensitivity analysis report)
“Reduced costs”:
How much final value will drop (or increase) if the variable cell was to increase by 1.
Alternative - have to change before we would consider making the product.
“Objective Coefficient”
Optimal quantity of decision variables X change in coefficient
- multiple number of final values
“Allowable increase/decrease”
= how much the coefficient can increase (or decrease) without having to change the entire system.