1Descriptive Statistics 34/6/2011Announcements•Chapter 11 HW due Friday–Skip m. and n. (plots)•Bring calculators from now onCentral Tendency•Compute the mode, median, and mean for eachof these data sets:Data set #1Data set #2iYiY151125243535454555510Central Tendency•Data set #1–Mode = 5–Median = 5–Mean = 5•Data set #2–Mode = 5–Median = 5–Mean = 5•Clearly, the two datasets are not identical•But central tendencybelies the truthOther measures of dispersal•Standard Deviation and Variance–Measures of dispersion around the mean.
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2Mean Absolute DeviationAverage distance of observations from mean.1. Calculate mean.2. Subtract the mean from each observationslvalue.3. Take the absolute values of those.4. Add up the differences.5. Divide by n (number of observations).