How are radicals used in everyday life?

Answer 1

I sometimes use radicals for a quick and dirty error estimation on a questionable statistic, especially in Baseball. Very roughly speaking, the error of a stat is its radical (square root), e.g. if a batter is 4 for 10 against a particular pitcher, the announcers sometimes get a little crazy and start lauding his .400 average!. Well I say, wait a minute, roughly speaking, those four hits have an error of plus or minus two hits for every 10 at bats. That gives an acceptable batting average range within error of .200 to .600, which basically tells you that you clearly don't have enough data yet to make any sort of analysis on that stat.