Lesson 8 - Shapes

# With a bimodal shape it is often best to analyze each

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Unformatted text preview: . With a bimodal shape, it is often best to analyze each “group” separately. Question: Which measure of the spread is influenced more by skewed data and outliers? Answer: The standard deviation is affected more by skewed data and outliers than the quartiles as it uses the mean in its calculation and the mean is influenced by skewed data and outliers. Therefore, the quartiles should be reported when data are skewed or when there are outliers since the quartiles are resistant to skewed data and outliers Although a box-and-whisker plot can be used to display data for quantitative variables, it is primarily useful when data are skewed or when there are outliers as it displays measures of center and spread that are resistant to skewness and oultiers (quartiles and median). Density Curves and the Normal Distribution : Go to page 12-1 in the Lesson Book : Learn About Density Curves More notes, comments, and other information: Recall that a way to determine the shape of data is to connect the midpoints of the tops of each bar of a histogram with a smooth line....
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## This document was uploaded on 02/15/2014 for the course STAT 351 at Oregon State.

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