According to economists, this episode of great recession was resulted from a sudden busting of house bubble in US, where the house bubble was caused by rapid growth of improper regulation on sub-prime mortgages (Merriam 2009; Wang 2009; Whitney 2007).
When working with equations that have two variables, the coordinate plane is an important tool. It's a way to draw pictures of equations that makes them easier to understand. To create a coordinate plane, start with a sheet of graph or grid paper. Next, draw a horizontal line.
Previously we considered the distribution of a single quantitative variable. Now we will study the relationship between two variables where both variables are qualitative, i.e. categorical, or quantitative. When we consider the relationship between two variables, there are three possibilities: Both variables are categorical.