Current location - Training Enrollment Network - Mathematics courses - What does "mathematical expectation" mean?
What does "mathematical expectation" mean?
Mathematical expectation is an important numerical feature, which reflects the average value of random variables and is the sum of the probabilities of each possible result multiplied by its result in the experiment. The word "expectation" here comes from gambling, which probably refers to how much money you expect to win when you bet.

Looking at the problem from the perspective of big data reflects the law of a large number of experiments in mathematical expectations. You can't just look at the present or special cases. You can't jump to conclusions about a phenomenon too early. You should listen and watch more to get a hidden rule.

Look at the probability weight in the mathematical expectation corresponding to the light problem with high probability. The value corresponding to the high probability has a great influence on the final result, so when you have a goal, in order to achieve it, you must find a path with the highest probability.

Extended data

Application:

1) random stock trading

Random stock picking is to pick a stock in the stock market with your eyes closed. Assuming that both the stop loss line and the take profit line are 10%, because it is random stock picking, the winning rate is equal to the loss rate, and because of stamp duty, commission and handling fee, the winning rate is equal to the loss rate.

2) Trend stock trading

Trend stock trading is based on inertia theory, and the winning rate has a great relationship with experience. Basically, it can be assumed that the average winning rate is 60% and the odds are 40%. Trend investors generally follow the principle of making money and running when losing money, such as take profit 10% and stop loss of 50%. The mathematical expectation is EP = 60% * 10.

Only stop loss line

3) Value investment

Because the value is underestimated and the winning rate is relatively high, a margin of safety is reserved for value investment, that is, the upward space is huge and the downward space is limited, so the expected value of mathematics must be positive.

Baidu Encyclopedia-Mathematical Expectation