Lesson 1

Lesson 1 - some way from the population. Two completely...

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Lesson 1 1. A major difficulty with scientific data is that they are subject to random variation, or uncertainty. Statistics is the field of study concerned with collection, analysis, and interpretation of uncertain data. Statistics allow scientists and engineers to design valid experiments and to draw reliable conclusions from the data they produce. A population is the entire collection of objects or outcomes about which information is sought, and a sample is just a subset of the population, it contains the objects or outcomes that are actually observed. There are tangible and conceptual populations. Simple random sampling is the best way to sample because it is reliable. A sample of convenience is a sample that is not drawn by a well-defined random method. They differ systematically in
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Unformatted text preview: some way from the population. Two completely random samples from the same population will not produce identical results because of sampling variation. The items in a sample are independent if knowing the values of some of the items does not help to predict the values of the others. The exception occurs when the population is finite and the sample comprises a substantial fraction of the population. In a one-sample experiment, there is only one population of interest, and a single sample is drawn from it. In a multisample experiment, there are two or more populations of interest and a sample is being drawn from each population. Numerical deals with amounts, numbers, etc. Quantitative deals with quantities. Categorical is categories, and qualitative is qualities....
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This note was uploaded on 02/18/2010 for the course ME 250 taught by Professor Roach during the Winter '10 term at BYU - ID.

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