1. Preliminaries Remember the setup: We (the RAF in World War II) want to know the number of warplanes fielded by the Germans. That number is N. The warplanes have serial numbers from 1 to N, so N is also equal to the largest serial number on any of the warplanes. We only see a small number of serial numbers (assumed to be a random sample with replacement from among all the serial numbers), so we have to use estimation. Question 1.1 Is N a population parameter or a statistic? If we compute a number using our random sample that's an estimate of N, is that a population parameter or a statistic?