1 Polyps: Benign growths in the uterine lining (endometrium) can cause a heavy or prolonged period. 2  Ovary dysfunction: Lack of ovulation (anovulation) results in a lack of progesterone, causing heavy periods. 3  Adenomyosis: When glands from the uterine lining embed in uterine muscle, heavy bleeding can occur.
Mean and Variance of Random Variables. The mean of a random variable provides the long-run average of the variable, or the expected average outcome over many observations.
In more advanced mathematics, a variable is a symbol that denotes a mathematical object, which could be a number, a vector, a matrix, or even a function. In this case, the original property of variability of a variable is not kept (except, sometimes, for informal explanations).