EC255 Lecture Notes - Lecture 3: Central Tendency, Standard Deviation, Average Absolute Deviation
Document Summary
Numerical data properties: central tendency, location, variation, dispersion, shape. Ungrouped data: provide information about the center or middle part of a group of numbers, provide location information, common measures, mode, median, mean. Mode: the mode is the value that occurs most frequently, not affected by extreme values, used for either numerical or categorical data, there may be no mode, there may be several modes. Median: middle value in an ordered array of numbers, applicable for ordinal, interval, and ratio data, not applicable for nominal data, not affected by extreme values, recipe, arrange observations in an ordered array. If there is an odd number of terms, the median is the middle term. If there is an even number of terms, the median is the average of the middle two terms. Mean: the most common measure of central tendency, mean = sum of values divided by the number of values, affected by extreme values (outliers, not applicable for nominal or ordinal data.
