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.
Variance. The Variance is defined as: The average of the squared differences from the Mean. To calculate the variance follow these steps: 1  Work out the Mean (the simple average of the numbers). 2  Then for each number: subtract the Mean and square the result (the squared difference).ariance. The Variance is defined as: The average of the squared differences from the Mean. To calculate the variance follow these steps: 1  Work out the Mean (the simple average of the numbers). 2  Then for each number: subtract the Mean and square the result (the squared difference).