Laughing Gas (1914 film) squabbling. The dentist arrives, and his first patient goes in, obviously in pain. The dentist prepares the nitrous oxide anaesthesic (also known commonly as "laughing gas" due to its effects prior to and after unconsciousness). With the man unconscious he pulls his tooth, but then he can't get him to wake up. He calls for Charlie and when he arrives the dentist runs off. Charlie tries to wake him and eventually tries hitting his head with a mallet. The man revives but starts laughing. Charlie knocks him out with the mallet. The dentist then returns and Charlie is sent to
Algebraic formula for the variance for the "n" by "m" cross-covariance matrix "between" two random vectors of length "n" and "m": where expectations are taken element-wise and formula_8 and formula_9 are random vectors of respective lengths "n" and "m". Note that this formula suffers from the same loss of significance as the formula for variance if used for calculating estimates of the covariance, and alternative algorithms should be used instead. Algebraic formula for the variance In probability theory and statistics, there are several algebraic formulae for the variance available for deriving the variance of a random variable. The usefulness of these depends on what is