Usually, high school math expectations are placed in the topic of the distribution list.

Above the distribution list are items, and below are probabilities.

Multiplying each term by the corresponding probability, and then adding them together is the mathematical expectation.

The same topic as the average in primary school ~ ~ It's very simple ~ ~ I hope the landlord will work hard to lay a good foundation in mathematics ~ The math score in the college entrance examination is 120, which are all basic points ~

I will go to the college entrance examination battlefield tomorrow ~ ~ ~ ~ hehe.