Published on January 22, 2016
For more course tutorials visit www.uophelp.com 1. For the following pair of variables, which more naturally is the response variable and which is the explanatory variable? College grade point average (GPA) and High school GPA 2. Use the points on the right to answer the following questions. a. Find the scores on x and y for each point. Comment on how zx and zy relate to each other for each point. b. Compute r using the z-scores for the four observations. Is this the value you expected to get for r? Why? 3.Match the scatterplots to the right with the correlation values. 1. r=0.9 2. r=0.58 3. r=0 4. The data on the right shows the percent of the population in a country that uses cell phones and their GDP. Let y = cell-phone use x = GDP. a. The graph on the right shows a scatterplot. Describe this plot in terms of the variability of cell-phone use values for nations close to 0 on GDP. Identify the nation that has less cell-phone use than you would expect, given their GDP. b. Give the x- and y- coordinates for the nation that has the highest cell-phone use. Give the x- and y- coordinates for the nation that has the highest GDP.