More on the Facebook friends study. Refer to the Facebook friends study that we began to examine in Example 12.3 (page 648). The explanatory variable in this study is the number of Facebook friends, with possible values of 102, 302, 502, 702, and 902. When using analysis of variance we treat the explanatory variable as categorical. An alternative analysis is to use simple linear regression. Perform this analysis and summarize the results. Plot the residuals from the regression model versus the number of Facebook friends. What do you conclude? F

Week 4: Bivariate Data 27 September 2016 Basic Statistics for Research Professor HK Dong Wendy Liu Bivariate/multivariate data – observations on two or more variables Marginal totals – total frequency of any row or column of a data table, given in the right-hand margin or bottom margin Simpson’s paradox – reversal of conclusions from a data table after combining several data tables together due to appearance of unreported variables Experimentation Random assignment – subjects placed randomly into control/experimental groups Placebo effect – subject’s expectations of a treatment to work cause positive results, even though the treatment itself has no therapeutic value o Placebo – treatment that has no physiological effect; usually a sugar pill,