STATS 250 Lecture Notes - Lecture 5: Confounding, Independent And Identically Distributed Random Variables, Confidence Interval
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STATS 250 Full Course Notes
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Chapter 2: sampling, surveys and gathering useful data. Descriptive statistics describing data using numerical and graphical summaries: mean, iqr, histograms, bar graphs. Inferential statistics using sample information to infer conclusions about a population. The objective is usually to use a small representative sample to infer information about the population. Population entire group of items/individuals that we want information about. Sample the smaller group of a population that we examine to gather information. Variable the characteristic that we want to learn about. Ex: a basket of balls is the population. We select a few random balls from the basket as our sample. The sample must be random with respect to the question at hand. Opinions collected from a random sample of 1000 adults in the state. Opinions collected from a random sample of parents of high school students in the state. Parents of high school students will be biased.