COMM 101 Lecture Notes - Lecture 18: Interquartile Range, Standard Deviation, Central Tendency
28 Aug 2016
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Document Summary
Measures of distribution: central tendency and dispersion let us describe what we are seeing in these kinds of. Gures: central tendency: where the most data are. Example: 2, 2, 2, 3, 3, 4, 6, 8, 15: mean: 5, median: 3, mode: 2. Can calculate mode for all kinds of variables. Can calculate median for ordinal, interval, and ratio variables. Can calculate mean for interval and ratio variables. Take away #2: descriptive statistics give a window into your data: dispersion: how spread-out the data are. Standard deviation: general measure of dispersion: tells you how far you need to go (in both directions) from the mean to capture certain amounts of data. 66% of the data will be within 1 standard deviation. 95% of the data will be within 2 standard deviations. 99% of the data will be within 3 standard deviations. Range (max and min): full range of the data: where the lowest and highest data points are.
