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1、Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-1,Business Statistics: A Decision-Making Approach 6th Edition,Chapter 1 The Where, Why, and How of Data Collection,Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-2,Chapter Goals,A
2、fter completing this chapter, you should be able to: Describe key data collection methods Know key definitions: Population vs. Sample Primary vs. Secondary data types Qualitative vs. Qualitative data Time Series vs. Cross-Sectional data Explain the difference between descriptive and inferential stat
3、istics Describe different sampling methods,Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-3,Descriptive statistics Collecting, presenting, and describing data Inferential statistics Drawing conclusions and/or making decisions concerning a population based only on
4、 sample data,Tools of Business Statistics,Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-4,Descriptive Statistics,Collect data e.g. Survey, Observation, Experiments Present data e.g. Charts and graphs Characterize data e.g. Sample mean =,Business Statistics: A De
5、cision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-5,Data Sources,Primary Data Collection,Secondary Data Compilation,Observation,Experimentation,Survey,Print or Electronic,Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-6,Survey Design Steps,Define the iss
6、ue what are the purpose and objectives of the survey? Define the population of interest Formulate survey questions make questions clear and unambiguous use universally-accepted definitions limit the number of questions,Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap
7、 1-7,Survey Design Steps,Pre-test the survey pilot test with a small group of participants assess clarity and length Determine the sample size and sampling method Select Sample and administer the survey,(continued),Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-8
8、,Types of Questions,Closed-end Questions Select from a short list of defined choices Example: Major: _business _liberal arts _science _other Open-end Questions Respondents are free to respond with any value, words, or statement Example: What did you like best about this course?Demographic Questions
9、Questions about the respondents personal characteristicsExample: Gender: _Female _ Male,Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-9,A Population is the set of all items or individuals of interestExamples: All likely voters in the next election All parts prod
10、uced todayAll sales receipts for NovemberA Sample is a subset of the populationExamples: 1000 voters selected at random for interviewA few parts selected for destructive testingEvery 100th receipt selected for audit,Populations and Samples,Business Statistics: A Decision-Making Approach, 6e 2005 Pre
11、ntice-Hall, Inc.,Chap 1-10,Population vs. Sample,a b c d ef gh i jk l m no p q rs t u v wx y z,Population,Sample,b c g i no r uy,Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-11,Why Sample?,Less time consuming than a census Less costly to administer than a censu
12、s It is possible to obtain statistical results of a sufficiently high precision based on samples.,Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-12,Sampling Techniques,Convenience,Samples,Non-Probability Samples,Judgement,Probability Samples,Simple Random,Systema
13、tic,Stratified,Cluster,Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-13,Statistical Sampling,Items of the sample are chosen based on known or calculable probabilities,Probability Samples,Simple Random,Systematic,Stratified,Cluster,Business Statistics: A Decision
14、-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-14,Simple Random Samples,Every individual or item from the population has an equal chance of being selected Selection may be with replacement or without replacement Samples can be obtained from a table of random numbers or computer random number g
15、enerators,Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-15,Stratified Samples,Population divided into subgroups (called strata) according to some common characteristic Simple random sample selected from each subgroup Samples from subgroups are combined into one,
16、Population Divided into 4 strata,Sample,Business Statistics: A Decision-Making Approach, 6e 2005 Prentice-Hall, Inc.,Chap 1-16,Decide on sample size: n Divide frame of N individuals into groups of k individuals: k=N/n Randomly select one individual from the 1st group Select every kth individual thereafter,Systematic Samples,N = 64 n = 8 k = 8,
