Understanding Moments

standard deviation provides an estimate of the average difference of each value from the mean.

The goal, then, should be to understand variation and, more importantly, to differentiate between the two types of variation. One kind is predictable and can be planned for. The other kind can’t be predicted. Sometimes it can be addressed, but some events are “black swans,” freak occurrences that may never happen again. The key is understanding the

A parameter is a value that describes a characteristic of an entire population, such as the population mean.

Pitfall #2: Looking at the wrong measure of center