A researcher is conducting a study to determine how knowledg
     A researcher is conducting a study to determine how knowledgeable teenagers are about making good food choices. She decides to interview teenagers eating at a fast food restaurant. Why might the results be biased?  Because they were taken from a stratified sample.  Because they were taken from a census.  Because they were taken from a convenience sample.  Because they were taken from a voluntary response sample.  Because they were taken from a simple random sample. 
  
  Solution
(C) this was convenience sample, and may not represent the population

