英文商务统计学ppt-第五章Ch05.ppt

Business Statistics: A First Course, 5e ? 2009 Prentice-Hall, Inc.Chap 5-1Chapter 5Some Important Discrete Probability DistributionsBusiness Statistics:A First Course5th Edition Business Statistics: A First Course, 5e ? 2009 Prentice-Hall, Inc.Chap 5-2Learning ObjectivesIn this chapter, you learn: The properties of a probability distributionTo calculate the expected value and variance of a probability distributionTo calculate probabilities from binomial and Poisson distributionsHow to use the binomial and Poisson distributions to solve business problems Business Statistics: A First Course, 5e ? 2009 Prentice-Hall, Inc.Chap 5-3DefinitionsRandom VariablesA random variable represents a possible numerical value from an uncertain event.Discrete random variables produce outcomes that come from a counting process (e.g. number of courses you are taking this semester).Continuous random variables produce outcomes that come from a measurement (e.g. your annual salary, or your weight). Business Statistics: A First Course, 5e ? 2009 Prentice-Hall, Inc.Chap 5-4DefinitionsRandom VariablesRandom VariablesDiscrete Random VariableContinuousRandom VariableCh. 5Ch. 6DefinitionsRandom VariablesRandom VariablesDiscrete Random VariableContinuousRandom VariableCh. 5Ch. 6DefinitionsRandom VariablesRandom VariablesDiscrete Random VariableContinuousRandom VariableCh. 5Ch. 6 Business Statistics: A First Course, 5e ? 2009 Prentice-Hall, Inc.Chap 5-5Discrete Random VariablesCan only assume a countable number of valuesExamples: Roll a die twice Let X be the number of times 4 occurs (then X could be 0, 1, or 2 times)Toss a coin 5 times. Let X be the number of heads (then X = 0, 1, 2, 3, 4, or 5) Business Statistics: A First Course, 5e ? 2009 Prentice-Hall, Inc.Chap 5-6Probability Distribution For A Discrete Random VariableA probability distribution for a discrete random variable is a mutually exclusive listing of all possible numerical outcomes for that variable and a pro