PPT-Correlation and

Linear Regression Chapter 13 Learning Objectives LO131 Explain the purpose of correlation analysis LO132 Calculate a correlation coefficient to test and interpret the relationship between two variables. and regression. Scatter plots. A scatter plot is a graph that shows the relationship between the observations for two data series in two dimensions.. Scatter plots are formed by using the data from two different series to plot coordinates along the . Chapter 10. Outline . Section 10-1 Introduction. Section 10-2 Scatter Plots. Section 10-3 Correlation. Section 10-4 Regression. Section 10-5 Coefficient of Determination and Standard Error of the Estimate. ... beware. Definition. Var. (X+Y) = . Var. (X) + . Var. (Y) + 2·Cov(X,Y). The . correlation. between two random variables is a dimensionless number between 1 and -1.. Interpretation. Correlation measures the . Week 1. Data Relationships. Finding a relationship between variables is what we’re looking for when extracting data from sample populations. . Is education better or worst now than before?. Do students learn better with the use of technology in the classroom?. Coefficient. &. Line of Best Fit. . We first need to make . sure the . calculator is . CL. ea. R. . of all . previous content. . We first need to make . sure the . calculator is . CL. ea. R. . What is correlation?. How to compute?. How to interpret?. This week. 2. The relations between two variables. How the value of one variable changes when the value of another variable changes. A correlation coefficient is a numerical index to reflect the relationship between two variables.. Var. (X Y) = . Var. (X) . Var. (Y) 2·Cov(X,Y). The . correlation. between two random variables is a dimensionless number between 1 and -1.. Interpretation. Correlation measures the . strength. of the . a measure of the extent to which two variables change together.. How well does A predict B?. The correlation may be positive, negative, or have no relationship.. Correlation. A . positive correlation . Summary of the measure of the characteristics of individuals in groups.. A descriptive statistic talks about a single characteristics within a given group. Lots of descriptive statistics are summarizing lots of characteristics but all within a given group.. Cartoon from xkcd.com. What is Correlation?. When two things go together:. cookies & milk. macaroni & cheese. peanut butter & jelly. What is . Statistical. Correlation?. A mutual relationship between two . Categorical variable: Yes-No, F-M. Ratio or interval variable: No. of incidents, lost days, or grade. Formula. Example. Hypothesis. . Setup. Ho: There is no relationship between respondent gender and earned score. Mary Forsythe, Graeme Kelly, Javier Garcia Pereda. IWW14, 24/04/2018. www.metoffice.gov.uk © Crown Copyright 2017, Met Office. © Crown copyright Met Office. Simple Linear Regression. April 17, 2018. Correlation . analysis* . M. easuring the degree . of association between two . continuous variables. , x and . y. We . have a . linear relationship. between x and y . Absolute vs. Relative . Age. Relative Age. Determining the age of an object in relation to other objects. “Estimate”. Index Fossils, Rock layers. Example. : A friend tells you . he . has 2 brothers – one that’s older than .