1. Each of the following sampling procedures is to be classified as producing a random sample or as producing a biased sample. Consider each case and decide whether the procedure is random or biased.
2. The population about which the inference is to be made is a population of scores in skeet shooting, and the question to be decided is whether men achieve higher scores than women. The investigator selects 10 men and 10 women at random; she then obtains 5 scores from each, making a sample of 100 scores. Is this a random sample?
3. Examining the same issue, a new investigator takes 100 averages of 5 scores, each average coming from a different randomly selected person. Is this sample of average scores a random sample?
4. The population of interest concerns attitude scores at Drexel University. The investigator wishes to obtain a sample of about 100 scores. He selects four classes at random whose total enrollment is 100 and obtains the attitude scores from these individuals. Is this a random sample?
5. A different investigator, also interested in attitude scores, creates a survey in the AEFIS software system and using the online student directory, takes every 75th name after randomly choosing a starting point and recruits 100 participants by e-mail. Seventy-one completed tests are submitted; the other 29 students failed to participate. Is the original list a random sample? Is the sample of 71 tests a random sample?