The purpose of this Decisions Project is to decide on two quantitative variables, see how the relationship between these variables has changed over time, and determine the most current relationship between the variables.
1. Watch the video by Hans Rosling titled “Let My DatasetChange Your Mindset” at http://www.ted.com/talks/lang/eng/  hans_rosling_at_state.html.
(a) Describe the “We” versus “Them” discussion in the video.
(b) In the video, there is a scatter diagram drawn between life expectancy and children per woman. Which variable is the explanatory variable in the scatter diagram? What type of relation exists between the two variables? How has the relationship changed over time when considering “We” versus “Them”?
2. Click the Data tab on the GapMinder website. Download the data for life expectancy and children per woman. Draw a scatter diagram of the data. Determine the linear correlation coefficient between the two variables. Be careful; some countries may not have both variables measured, so they will need to be excluded from the analysis.
3. Find the least-squares regression line between life expectancy and children per woman. Interpret the slope of the regression line.
4. Is the life expectancy of the United States above or below average given the number of children per woman?
5. Choose any two variables in the GapMinder library and write a report detailing the relationship between the variables over time. Does the data reflect your intuition about the relationship?