In 41 patients, all hyperfunctioning parathyroid tissue was resected at the time of surgery and confirmed by a corresponding decrease in the intraoperative postexcision rapid PTH determination as well as by subsequent normalization of postoperative serum calcium and PTH levels and resolution of clinical symptoms.
In other words, the standard deviation Ï (sigma) is the square root of the variance of X; i.e., it is the square root of the average value of (X â Î¼) 2. The standard deviation of a (univariate) probability distribution is the same as that of a random variable having that distribution.
The formula of population variance is sigma squared equals the sum of x minus the mean squared divided by n. I don't know about you, but that sounds and looks like Greek to me. So let's break this down into some more manageable steps. 1  Find the mean of the set of data. 2  Subtract each number from the mean.