One Friday morning at a television manufacturing company the quality inspector recorded the grades assigned to the pictures on the television sets that were ready to be shipped. The grades, presented in DS 6.1.2, are perfect," "good," "satisfactory," or "fail."
(a) Define the population from which the sample is taken. Do you think that it is a representative sample?
(b) Are there any other factors that should be taken into account in interpreting the data set? Are there any issues pertaining to the way in which the sample has been collected that you would want to investigate before interpreting the data set?