In probability theory and mathematical statistics, if the value of random variable X is [1, 2,3] and the probability distribution is [0.2, 0.5, 0.3], then the expectation of this random variable X is =10.2+20.5+3 * 0.3 = 2./kloc-.
It can be seen that in higher mathematics, the unity of probability is dead and the same;
In probability theory and mathematical statistics, probability is generally unequal, otherwise it is unnecessary to use the knowledge of probability theory.