Search results
Results From The WOW.Com Content Network
Independence is a fundamental notion in probability theory, as in statistics and the theory of stochastic processes.Two events are independent, statistically independent, or stochastically independent [1] if, informally speaking, the occurrence of one does not affect the probability of occurrence of the other or, equivalently, does not affect the odds.
Then the random variables and are uncorrelated, and each of them is normally distributed (with mean 0 and variance 1), but they are not independent. [ 7 ] : 93 It is well-known that the ratio C {\displaystyle C} of two independent standard normal random deviates X i {\displaystyle X_{i}} and Y i {\displaystyle Y_{i}} has a Cauchy distribution .
Independent: Each outcome of the die roll will not affect the next one, which means the 10 variables are independent from each other. Identically distributed: Regardless of whether the die is fair or weighted, each roll will have the same probability of seeing each result as every other roll. In contrast, rolling 10 different dice, some of ...
If , are two independent normal deviates with mean and variance , and , are arbitrary real numbers, then the variable = + (+) + + is also normally distributed with mean and variance .
A product distribution is a probability distribution constructed as the distribution of the product of random variables having two other known distributions. Given two statistically independent random variables X and Y, the distribution of the random variable Z that is formed as the product = is a product distribution.
Two random variables and are conditionally independent given a random variable if they are independent given σ(W): the σ-algebra generated by . This is commonly written: This is commonly written: X ⊥ ⊥ Y ∣ W {\displaystyle X\perp \!\!\!\perp Y\mid W} or
This means that the sum of two independent normally distributed random variables is normal, with its mean being the sum of the two means, and its variance being the sum of the two variances (i.e., the square of the standard deviation is the sum of the squares of the standard deviations). [1]
Further, two jointly normally distributed random variables are independent if they are uncorrelated, [4] although this does not hold for variables whose marginal distributions are normal and uncorrelated but whose joint distribution is not joint normal (see Normally distributed and uncorrelated does not imply independent).