4. What is the standard deviation of upward mobility (populationweighted) in your chosen county? Is it larger or smaller than the standard deviation across tracts in your state? Across tracts in the country? What do you learn from these contparisons? 5. Now let's turn to downward mobility: repeat questions (3) and {4] looking at children who start with parents at the TSth and lth percentiles. How do the patterns differ