stat tutor section 2 notes

# stat tutor section 2 notes - CONCEPT SHEET FOR DESCRIPTIVE...

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CONCEPT SHEET FOR DESCRIPTIVE STATISTICS TUTORIAL Sampling Sampling is the random selection of a subset of objects/events from a larger population. Inferences to the population are based on conclusions made about the sample. Data are records made from a sample of objects/events. Individual data are called replicates . Descriptive statistics includes methods for transforming data in order to better understand it. A bell-shaped or normal data distribution usually results when a random sample is drawn from a larger population. Normal Curve The mean , median , and mode are descriptive parameters that characterize a sample’s central value. The mean ( X ) is the sum of all data values ( x i ) divided by the sample size n or × = Σ× i / n The median is the middle data value at position (n + 1)/2 when the data are ordered. The range , variance and standard deviation are descriptive parameters that characterize a sample’s variability. The range is the smallest data value subtracted from the largest value.
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## This note was uploaded on 10/04/2008 for the course BIO G 1103 taught by Professor Ransler during the Fall '07 term at Cornell University (Engineering School).

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