Another way to select a random sample is as follows:
Insert a column in Excel. Go to Tools - Data Analysis and select random number generation. Set the distribution to uniform and the number range 0 to 1. Set the output range to be the same as the column you inserted previously. This function will product a random number for each record. You then sort your data by the random number field, which, in effect, puts your entire population in random order. If your sample size is 25, just take the first 25 on the list. If you decide to expand your sample from 25 to 35, just take the next 10 on the list (again, the records are in random order) rather than so through another sample selection process. Need to expand the sample again due to errors found, just keep going down the list in order.
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