STAT 201 Chapter Notes - Chapter 3.1: Dependent And Independent Variables, Standard Deviation, Scatter Plot
10 Jan 2017
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Contingency table= display for 2 categorical units; rows list the categories of one variable, columns list categories of other variable. Cross tabulation= process of taking a data file and finding the frequencies for the cells of a contingency table. Conditional proportions in each row sum to 1. Proportion of all of a sample isn"t a conditional proportion. Marginal proportion= found using counts in the margin of the table. Independent= when proportions for 2 conditions are the same. When investigating association, 3 types of cases: Variables could be categorical: data is displayed in contingency table, compare conditional proportions. Income and gender: compare categories using center and variability for quantitative variable, graphics like side-by side box plot. Both variables could be quantitative: analyze how outcome on response variable tends to change as value of explanatory variable changes. Scatterplot= graphical display for 2 quantitative variables using horizontal axis for explanatory variables and vertical axis for response variable.
