Probability distribution refers to the probability law used to describe the value of random variables.The probability of an event indicates the probability of a certain result occurring in a test.If you want to fully understand the test, you must know all possible results of the test and the probability of various possible results, that is, the probability distribution of random tests.If the test result is expressed by the value of variable X, the probability distribution of random test is the probability distribution of random variable, that is, the possible value of random variable and the probability of obtaining the corresponding value.According to the different types of random variables, the probability distribution takes different forms.[1]
The law of probability distribution is called probability law or probability distribution for short.
The probability measure describing the value rule of random variables.assume
Is the probability space
The random variable on the
Defined
The set function F on is a probability measure, called random intersection quantity
The probability distribution law of.For any
random variable
The probability of falling into B can be obtained by calculating the measure F (B) of B, which means that the probability distribution F completely characterizes
Probability law of value taking.[2]
Normal distribution
Announce
edit
Normal distribution is very importantContinuous random variableThe probability distribution of.There are many variables in biological phenomena that obey or nearly obey normal distribution, such as body length, body weight, milk yield, wool yield, hemoglobin content, blood sugar content, etc. of domestic animals.Many statistical analysis methods are based on normal distribution.In addition, under certain conditions, the normal distribution is the limit distribution of the probability distribution of many random variables.Therefore, in statistics, normal distribution plays an important role in both theoretical research and practical application.
For the probability calculation of normal distribution, we start from the standard normal distribution.This is because, on the one hand, standard normal distribution has the simplest form in normal distribution, and any normal distribution can be converted into standard normal distribution for calculation;On the other hand, people haveStandard normal distributionThe distribution function of is compiled into a normal distribution table for direct reference.
