Dirichlet also tried to estimate th

Dirichlet also tried to estimate the error of the approximation. This attempt was not
a very successful one and his technique differed heavily from modern techniques. It
was, however, the first attempt to try to estimate the error of the approximation.
Dirichlet had estimated the errors for other non-probabilistic approximations before
and he showed that those same techniques could be applied to probability theory as
well as they had been to "pure" mathematics