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GIÁO TRÌNH MARKETING NGHIÊN CỨU - PHẦN 16

Tham khảo tài liệu 'giáo trình marketing nghiên cứu - phần 16', kinh doanh - tiếp thị, tiếp thị - bán hàng phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Generalizing a Sample’s Findings to Its Population and Testing Hypotheses About Percents and Means Statistics Versus Parameters Statistics: values that are computed from information provided by a sample Parameters: values that are computed from a complete census which are considered to be precise and valid measures of the population Parameters represent “what we wish to know” about a population. Statistics are used to estimate population parameters. Ch 16 Ch 16 The Concepts of Inference and Statistical Inference Inference: drawing a conclusion based on some evidence Statistical inference: a set of procedures in which the sample size and sample statistics are used to make estimates of population parameters Ch 16 Ch 16 How to Calculate Sample Error (Accuracy) sp Where z = 1.96 (95%) or 2.58 (99%) Ch 16 Accuracy Levels for Different Sample Sizes At 95% ( z = 1.96) n p=50% p=70% p=90% 10 ±31.0% ±28.4% ±18.6% 100 ±9.8% ±9.0% ±5.9% 250 ±6.2% ±5.7% ±3.7% 500 ±4.4% . | Generalizing a Sample’s Findings to Its Population and Testing Hypotheses About Percents and Means Statistics Versus Parameters Statistics: values that are computed from information provided by a sample Parameters: values that are computed from a complete census which are considered to be precise and valid measures of the population Parameters represent “what we wish to know” about a population. Statistics are used to estimate population parameters. Ch 16 Ch 16 The Concepts of Inference and Statistical Inference Inference: drawing a conclusion based on some evidence Statistical inference: a set of procedures in which the sample size and sample statistics are used to make estimates of population parameters Ch 16 Ch 16 How to Calculate Sample Error (Accuracy) sp Where z = 1.96 (95%) or 2.58 (99%) Ch 16 Accuracy Levels for Different Sample Sizes At 95% ( z = 1.96) n p=50% p=70% p=90% 10 ±31.0% ±28.4% ±18.6% 100 ±9.8% ±9.0% ±5.9% 250 ±6.2% ±5.7% ±3.7% 500 ±4.4% ±4.0% ±2.6% 1,000 ±3.1% ±2.8% ±1.9% The “p” you found in your sample 1.96 times sp 95% Confidence interval: p ± 1.96 times sp Ch 16 Parameter Estimation Parameter estimation: the process of using sample information to compute an interval that describes the range of values of a parameter such as the population mean or population percentage is likely to take on Ch 16 Parameter Estimation Parameter estimation involves three values: Sample statistic (mean or percentage generated from sample data) Standard error (variance divided by sample size; formula for standard error of the mean and another formula for standard error of the percentage) Confidence interval (gives us a range within which a sample statistic will fall if we were to repeat the study many times over Ch 16 Parameter Estimation Statistics are generated from sample data and are used to estimate population parameters. The sample statistic may be either a percentage, i.e., 12% of the respondents stated they were “very .