Group Quiz

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+0.25x2-0.5z. 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?

4. Generate a new variable that is the log of average income and call it logavginc. Regress testscr against logavginc. Which of the equations below describes the relationship between test scores (y) and income (x)?
5. Use no. 4 to answer this question. What is the effect of a $1k income increase on test scores in a district with an average income of 10k? What about a district with an average income of 20k?