Jointprobability for two events = Probability of first event (Pr1) x Conditional probability of second events (Pr2)
Rules in combining Probabilities
Probability either oneorboth two events occur = sum of seperate probabilities - joint probability
Rules in combining Probabilities
Probabilities for all possible mutually exclusive outcomes = single experiment must be add up to one.
Ex: 4 variables/ 1 = 0.25
V1=0.25, V2= 0.25, V3= 0.25, V4= 0.25
= 1
Discrete Distribution
Uniform Distribution - All outcomes are equally likely
Binomial Distribution - Each trial has only two possible outcomes ( accept or reject)
Bernoulli Distribution - Involves in one trial where it deals with many as necessary
Hypergeometric distribution - It used sampling without replacement
Poison Distribution - Event being studied may happen more than once with random frequency
Continuous Distribution
Normal Distribution - most important and useful of all probability distribution, describe many physical phenomena.
Exponential Distribution - Probability of zero occurence in a time period
T-distribution ( student distribution) - used small samples of population, less than 30
Chi square distribution - Test goodness of fit between actual data and theoretical distribution
Unknown population variance of T distribution
Large sample sizes - almost identical to standard normal distribution
Small sample size - only the standard deviation is known
T- distribution provides :
Reasonable estimate for test of population mean
Provides best estimates of variance than normal distribution
payoff decision tables
Identify best solution given several decision choices and future condition involves risk
Payoff table
Present outcomes of specific decision when certain states of nature occur
Perfect information
Knowledge of future state of nature will occur with certainty
Expected Value of Perfect Information ( EVPI)
EVPI = Expected value w/o perfect information - Return of best action taken given perfect information
Expected Value of Perfect Information
Amount of company is willing to pay for the market analyst errorless advice.
Decision Tree
Analytical tool which series of decision has to be made at various time intervals influenced by information available at the time it is made
Event of each act
Several decisions or acts and possible consequence that decision tree diagram show
Steps in making decisions tree
Identification of points and decision and alternatives available
Determination points of uncertainty and types of range on outcomes
Estimate . probabilities of different events
Estimates cost and gains of various events
Analysis of alternative value in chosing course of action.
Learning curves
Reflects increase of rates at which people Performed task as they gained experience, only applicable on each stage of production
Leaning Curves
Time requires is reduced by 20% to 40%, 20% is the most common
Simulation
Technique for experimenting with logical and mathematical models using a computer
Simulation Techniques
Experimentation is neither new nor uncommon in business. It is organized trial and error using model of the rela world to obtain information prior full time implementation
Simulation Techniques
Models classified into two:
Physical Models
Abstract Models - maybe pictorial, logical mathematics that is time consuming calculations and eliminated much of costly drudgery lead to grow of interest
Simulation procedure
Define objectives - they serve as a guideline, aid in understanding existing System and estimate behavior of some new system. What if questions whether to modify models.
Simulation Procedure
2. Formulate the model - include individual behavior and interrelationship must be define in precise logic mathematical terms.
2 KINDS OF MODEL
Controllable - decision maker influence
Probabilistics - involve circumstances beyond their control
Simulation procedure
3. Validate the model - Assurance that experiment be realistic require validation often using historical data