tailieunhanh - Lecture Marketing research essentials (9th Edition): Chapter 12 - McDaniel, Gates

Chapter 12 - Sample size determination. This chapter include objectives: Gain an appreciation of a normal distribution; understand population, sample, and sampling distributions; understand how to compute the sampling distribution of the mean. | Chapter Twelve 12-1 Budget Available: A valid factor – how much can we afford? Rule of Thumb: Is there some convention we can apply? What might make an adequate sample size? Sample Size for Probability Sampling 12-2 Key Terms & Definitions You might want to mention that the budget includes time as well as money, and some sample sizes and methods take longer than others to complete. Number of Subgroups Analyzed: In any sample size determination problem, consideration must be given to the number and anticipated size of various subgroups of the total sample that must be analyzed. Traditional Statistical Methods: Variance, standard deviation, and confidence interval play a key role. Sample Size for Probability Sampling 12-3 Key Terms & Definitions The professor might want to give an example or two of how the number of sub-groups affects sample size. You might want to include the incident rate of a population in an example. Central Limit Theorem: The idea that a distribution of | Chapter Twelve 12-1 Budget Available: A valid factor – how much can we afford? Rule of Thumb: Is there some convention we can apply? What might make an adequate sample size? Sample Size for Probability Sampling 12-2 Key Terms & Definitions You might want to mention that the budget includes time as well as money, and some sample sizes and methods take longer than others to complete. Number of Subgroups Analyzed: In any sample size determination problem, consideration must be given to the number and anticipated size of various subgroups of the total sample that must be analyzed. Traditional Statistical Methods: Variance, standard deviation, and confidence interval play a key role. Sample Size for Probability Sampling 12-3 Key Terms & Definitions The professor might want to give an example or two of how the number of sub-groups affects sample size. You might want to include the incident rate of a population in an example. Central Limit Theorem: The idea that a distribution of a large number of sample means or sample proportions will approximate a normal distribution - regardless of the distribution of the population from which they were drawn. Normal Distribution: The continuous distribution that is bell shaped and symmetrical about the mean. The mean, median, and mode are equal. Finally, about 68% of the observations are within one standard deviation plus/minus of the mean, 96% are within two standard deviations, and 99+% are within three standard deviations of the mean respectively. The Normal Distribution 12-4 Key Terms & Definitions Important Characteristics of a Normal Distribution 12-5 Key Terms & Definitions Bell-shaped and has only one mode. Symmetric about its mean Uniquely defined by its mean and standard deviation The total area under a normal curve is equal to one The area of a region under the normal distribution curve between any two values of a variable equals the probability of observing a value in that range when an observation is .