EC255 Lecture Notes - Lecture 11: Nonprobability Sampling, Statistic, Sampling Error
Document Summary
Reasons for taking a census: eliminate the possibility that by chance a random sample may not be representative of the population, for the safety of the consumer. Reasons for sampling: saves money and time, can broaden the scope of the data set, research process is sometimes destructive, the sample can save product. Inferential statistics: using data obtained through sampling to estimate the value of or test a hypothesis about a parameter (inductive logic, transform info into knowledge. Sampling distribution: a sampling distribution is a distribution of the possible values of a statistic for a given size sample selected from a population. Developing a sample distribution: assume there is a population, population size n=4, random variable, x, is age, values are x:18,20,22,24, summary measures for the population distribution, now consider all possible samples of size n=2. Sampling distribution of x-bar: proper analysis and interpretation of a sample statistic requires knowledge of its distribution.
