The adjective "rigorous" means attention to following rules and has the synonyms accurate, exacting. thorough, or meticulous. When the context is negative, it can mean strict, harsh, onerous, inflexible, or burdensome.
The mean distance is the same as the mean of a set of numbers,but this time, instead of them just being numbers, they're lengths. You just simply add up all the numbers and divide the total length,...