A list of 50 subjects is entered into a computer file and then sorted by last name. The subjects are assigned to five treatments by taking the first 10 subjects for Treatment 1, the next 10 subjects for Treatment 2, and so forth. Solution (a) People with last names close to each other might have characteristics in common. For example, relatives with the same last name. People of certain ethnic backgrounds may have a lot of similar names, like Mohammed, or Nguyen, or Smith..