If not all members of a population have a non-zero chance of ...

[james9437]

If not all members of a population have a non-zero chance of being selected for a sample, then
 
  a. the sample may not be representative of the population.
  b. there is a risk of inappropriately generalizing results beyond the sample.
  c. the sample has been chosen using nonprobability sampling.
  d. All of these are true.

Question 2

If your professor is only interested in the test performance of students in her class, the class is her
 
  a. Pppulation.
  c. biased sample.
  b. random sample.
  d. non-probability sample.

[tkempin]

Answer to Question 1

D

Answer to Question 2

A