The Ljung Box Test

The orignal paper Ljung-Box (1979) uses notation that we have not yet covered and it also contains some mathematical calculations that would take us too long to explain in detail. Fortunately it also contains a picture that is worth a thousand words.

In particular, if you look at page 299 you will see at a glance why one prefers the Ljung-Box statistic over the Box-Pierce statistic.