Year Number of Dropouts 1 7 2 8 3 6 4 6 5 6 6 4 7 4 8 1 9 2 10 7 11 6 12 1 13 1 14 1 15 3 16 3 17 5 18 4 19 5 20 7 The table gives 20 years of data on the number of students in a particular school who dropped out in the ninth grade. A sample is taken to include only the last 3 years of this data. With this information, calculate both the population mean and the sample mean for ninth-grade dropouts per year.
