Expected calculation: X is a discrete random variable, and all its possible values are a 1, a2, a3, etc. When an takes these values, the corresponding probabilities are p 1, p2, p3, etc. Pn, then its mathematical expectation e (x) = (a1) * (p1)+(a2) * (.

In probability theory and statistics, mathematical expectation is the sum of the probability of each possible result multiplied by its result in the experiment. It is also one of the most basic mathematical characteristics.

meaning

Reflect the average value of random variables. It should be noted that the expected value is not necessarily equal to the common sense "expectation"-"expected value" is not necessarily equal to every result. The expected value is the average of the output values of variables. The expected value is not necessarily contained in the set of output values of variables. The law of large numbers stipulates that as the number of repetitions approaches infinity, the arithmetic average of numerical values almost inevitably converges to the expected value.