ah.Sampling and Estimators - 1 Plan for the next few weeks Sampling Characteristics of sample statistics(estimators(Estimators are random variables

# ah.Sampling and Estimators - 1 Plan for the next few weeks...

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Plan for the next few weeks: Sampling Characteristics of sample statistics (estimators) (Estimators are random variables.) Confidence Interval Estimation Hypothesis Testing Sampling To some extent this is where “statistics” (as a discipline) really starts. The goal is to make meaningful statements about populations. But statisticians, or those using statistical analysis, must use samples to draw inferences about the population, because it usually is impractical (time consuming and expensive) to scrutinize the whole population. Drawing a sample Our goal is a sample that is representative of the population. The surest way to achieve this goal is to draw a simple random sample. In a simple random sample the probability that an element (person, car, whatever) is in the sample is 1/N. 1
There are many variations on simple random sampling, but all involve a strong element of randomness. Many polls, for example, rely on a technique known as multistage cluster sampling.