A genetic test examines the genetic information contained inside a person's cells, called DNA, to determine if that person has or will develop a certain disease or could pass a disease to his or her offspring.
Variance is non-negative because the squares are positive or zero. The variance of a constant random variable is zero, and if the variance of a variable in a data set is 0, then all the entries have the same value. Variance is invariant with respect to changes in a location parameter.That is, if a constant is added to all values of the variable, the variance is unchanged.ere Cov(â, â) is the covariance, which is zero for independent random variables (if it exists). The formula states that the variance of a sum is equal to the sum of all elements in the covariance matrix of the components.
For a Discrete random variable, the variance Ï2 is calculated as: For a Continuous random variable, the variance Ï2 is calculated as: In both cases f(x) is the probability density function. The Standard Deviation Ï in both cases can be found by taking the square root of the variance.or a Discrete random variable, the variance Ï2 is calculated as: For a Continuous random variable, the variance Ï2 is calculated as: In both cases f(x) is the probability density function. The Standard Deviation Ï in both cases can be found by taking the square root of the variance.