STAT 111 Study Guide - Final Guide: Test Statistic, Squared Deviations From The Mean, Simple Random Sample
Document Summary
Histograms do not display actual values observed (we prefer stemplots for small data sets) Shows the distribution of counts or percents among the values of a single variable (bar graphs are different because they compare the counts of different items) Use histograms of percents for comparing several distributions that have different numbers of observations. Look for the overall pattern and for striking deviations from the norm. Describe the overall pattern of a distribution by its shape (unimodal/bimodal/symmetric/skewed/bell), center, and spread. Mean and median for symmetric distributions are close together (if exactly symmetric, mean = median) 1. 5 iqr is used to determine outliers in data set. The sum of the squared deviations of any set of observations from their mean is the smallest that the sum of squared deviations from any number can possibly be. This is not true of the unsquared distances. So squared deviations point to the mean as center in a way that distances do not.
