1. A 2014 UNRWA report noted that the relationship between refugee camp overcrowding (x) and the prevalence of scabies (y) can be described by x=0.2y+4. If y=3x-10 describes the relationship between diarrhea incidence (y) and overcrowding (x), how dense are the camps where scabies is more prevalent than diarrhea?
2. Suppose the relationship between illnesses (y), density of families per block (x), and water availability (z) is y = 1-2x+0.25x^{2}-0.5z. What is the optimal number of families per block to minimize the spread of illnesses?
3. Open school.csv. Draw a scatterplot with test score (testscr) on the y axis and average income (avginc) on the x axis. Does this look like a linear relationship? Why, or why not?