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.
â¢ The square of the correlation coefficient, r^2 = the % of the TOTAL variance in the Y scores that be explained by X scores. --> it indicates the accuracy of prediction based on X. --> aka if we know variance of X, we can find out the variance of Y, which is why r is squared (ex.