Thompson and Randall-Maciver (1905) report four measurements of male Egyptian skulls from five different time periods. The first was maximal breadth of skull and the five time periods were 4000 BC, 3300 BC, 1850 BC, 200 BC, and 150 AD. The data are stored on the author’s web site in the file skull data.txt. The first four columns contain the skull measurements and the fifth column contains the time periods. For the data in column 1 (maximal breadth), perform all pairwise comparisons using means via the R function lincon. Hint: use the R function fac2list to divide the data in groups based on the time periods. Next, compare the groups using tmcppb when using a 20% trimmed mean and compare the results to those based on means compared via lincon.
