What is the range rule of thumb?

The range rule of thumb is a statistical rule used to estimate the standard deviation of a data set. It states that the range of a data set can be divided by four to give an approximate value for the standard deviation.

For example, if the range of a data set is 20, the standard deviation can be estimated as 20/4 = 5.

While the range rule of thumb can give a rough estimate of the standard deviation, it is not always accurate and may not be appropriate for skewed or non-normal distributions. It is best used as a quick and simple way to get a rough idea of the variability in a data set.