A population is all the data that exist for a process. A sample is a small group of data randomly taken from a population that is representative of the whole population.
Three statistical measures of variation are:
- The arithmetic average of the sample.
- This measures the location of the process output.
- The highest data point minus the lowest data point.
- This is one of two measures of the variation in the process.
- A statistic that measures how data cluster around the mean.
- This is another measure of variation.
- The smaller the standard deviation, the less variation there is in a process. The larger the standard deviation, the more variation there is in a process.