What is the mean value of decentralization

1. According to Hou Jietai: the so-called centralization refers to subtracting the mean value of a variable from its expected value. For sample data, each observation value of a variable is subtracted from the sample average value of the variable, and the transformed variable is centralized
for your question, subtract the mean from each measurement.

2. Centralization is to subtract the mean and Z-score is to divide it by the standard deviation. Both of them are centralization methods.

3. Yes, subtract the mean value of the cases corresponding to the project
and then use the data after centralization to do regression, instead of centralization and aggregation

5. The so-called data centralization refers to the data in the data set minus the mean value of the data set
for example, if there are data sets 1, 2, 3, 6 and 3, and the mean value is 3, then the data set after centralization is 1-3,2-3,3-3,6-3,3-3, that is: - 2, - 1,0,3,0. The purpose of data centralization is to eliminate the influence of dimension on data structure, because the unit of different variables is not the same, which will cause various statistical errors.

6. A. The average value of a group of data is not always positive, so this option is wrong
B. the variance of a group of data is non negative, so this option is wrong
C. subtract the average value from each number in a group of data, and then add up the difference. The sum must be zero, so this option is correct
D. the range of a group of data is not necessarily smaller than the variance, so this option is wrong
so C

7. The average is the average. I believe you can understand this concept. The sum of the measured values of n samples divided by N is the average value. As for the standard deviation of the mean, just remember the formula, s = under the root sign (sum of deviations divided by (n-1)). It's just a prescriptive formula. I also think it's more appropriate to divide the sum of deviation by N, so that when the sample number is 1, the deviation is zero, but the sample number of 1 is meaningless in actual proction, and the sample number is at least not less than 3. The specific derivation may need to read mathematics books. If you only remember the formula, you can turn over the books of analytical chemistry

8. It's not an error

9. Is the matrix minus the average or the vector in the matrix minus the average? Make it clear to answer your question