Laughing Gas (novel) and darling of all American mothers. Joey is also going to have a tooth out, but Joey is going to be operated on by B.K. Burwash, Zizzbaum's rival—they have a common waiting-room—exactly at the same time as Reggie. Presently reporters storm the dentist's practice to take photos of Joey and interview him. Both Reggie and Joey get laughing gas as anaesthetic. When Reggie regains consciousness he finds himself spoken to by B.K. Burwash, and also in the latter's chair. He concludes that there has been a switch in the fourth dimension: Joey's and his souls have changed bodies. Before he
Algebraic formula for the variance 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 already known about the random variable; for example a random variable may be defined in terms of its probability density function or by construction from other random variables. The context here is that of deriving algebraic expressions for the theoretical variance of a random variable, in contrast to questions of estimating the variance of a population from sample data for which there are special considerations