> a <- c(179,160,136,227) > sd(a) [1] 38.57892 > sqrt(sum((a-mean(a))^2/(length(a)-1))) [1] 38.57892. ```. ... <看更多>

To do the standard deviation, I loop through again, now that I have the mean calculated. I would like to avoid going through the array twice, ... ... <看更多>