An investigator wishes to estimate the average number of defects per board on boards of electronic components manufactured for installation in computers. The boards contain varying numbers of components, and the investigator thinks that the number of defects should be positively correlated with the number of components on a board. Thus, pps Number of Number of Department items Department items 1 129 31 2 9 10 26 3 27 11 22 4 40 12 19 5 35 13 16 6 15 14 33 7 18 15 6 8 10 286 Chapter 8 Cluster Sampling sampling is used, with the probability of selecting any one board for the sample being proportional to the number of components on that board. A sample of boards is to be selected from the boards of one day of production. The number of components on each of the ten boards are