Which of the following is NOT a reason to explain why infant mortality increased with the number of ...

Which of the following is NOT a reason to explain why infant mortality increased with the number of physicians?
 
  a. More physicians would lead to greater rates of reporting infant deaths.
  b. Physicians go where the problems are.
  c. Both variables are under the control of some third variable.
  d. All of these answers are possible.

Question 2

If we look at the correlation between college admissions test scores and subsequent performance in college for all admitted applicants, we are likely to
 
  a. underestimate the degree of correlation between test score and potential performance.
  b. overestimate the relationship.
  c. do quite a good job of estimating the relationship if our sample is sufficiently large.
  d. not know much more than when we began.