How to determine the sample size in sampling survey?

Calculation formula of variable population repeated sampling;

Attribute population repeated sampling:

(2) In the non-repetitive sampling mode:

Calculation formula of variable population non-repeated sampling;

Non-repeated sampling of attribute population:

Sample size refers to the number of units contained in a sample, which is generally expressed by n, which is a very important concept in sampling inference. The size of sample size is directly related to the accuracy of inference estimation, that is, under a given overall situation, the larger the sample size, the smaller the representative error of statistical estimator, and conversely, the smaller the sample size, the greater the estimation error. ?

Extended data

Estimation method of sample size in investigation and study: empirical method

(1) The sample size used to determine the normal range is at least greater than 100.

(2) The sample size of regional survey is usually 500~ 1000, and that of national survey is usually 1500~2500.

(3) The sample size of descriptive research is generally 10%~20% of the total.

(4) Explore the relationship between multiple independent variables and a dependent variable. The sample size is 10~20 times, preferably 20 times the number of independent variables.

Baidu encyclopedia-sample size