How to identify monopolistic suppliers

List of contents of this article:

• 1,How to identify monopolistic suppliers What is the error calculation formula?
• 2, How to calculate the standard error formula
• 3, Definition and calculation of error

What is the error calculation formula?

1. Absolute error = | display value - standard value | (i.e. the absolute value of the difference between the measured value and the real value) Relative error = | display value - standard value |/real value (i.e. the percentage of the real value of the absolute error) In addition, there are: system error: It is an error caused by measuring instruments, tools, fixtures, etc.

2. Calculate the error rate formula: w=F/S. Error is the measured value minus the reference value. The measured value is referred to as the measured value, which represents the measured value of the measurement result. The so-called reference quantity value is generally expressed by the true value of the quantity or the agreed quantity value. Classification of errors: Errors are divided into absolute errors and relative errors.

3. Where E is the error = measured value - real value.The difference from the standard deviation The meaning, function and scope of use of the standard deviation are different from the standard error.

4. Formula: If the error of n measured values is , then the standard error of this group of measured values is equal to: where E is the error = measured value - real value. The standard error is generally expressed by SE, which reflects the degree of variation of the sample average to the overall average, thus reflecting the size of the sampling error, which is an indicator of measuring the precision of the results.

5. The allowable error formula is nominal error = the largest absolute error/range *100%. According to the manufacturing quality of the instrument, the maximum error of various instruments is stipulated in the national standard, which is called the allowable error. The maximum allowable error refers to the error limit value allowed for a given measuring instrument, specifications, procedures, etc.

How to calculate the standard error

1, where E is the error = measured value - real value. The difference from the standard deviation The meaning, function and scope of use of the standard deviation are different from the standard error.

2. Calculation method of standard error: arithmetic square root of variance =s=sqrt ((x1-x)^2+(x2-x)^2+...(xn-x)^2)/(n-1). The standard error is generally used to determine the reliability of the group of measured data. Mathematically, its value is equal to the square root of the average sum of the squares of the measured value error.

3. The calculation formula of RSD is: relative standard deviation (RSD) = standard deviation (SD) / arithmetic average of the calculation result (X). Or: Relative standard deviation RSD is the coefficient of variation: the calculation formula of the coefficient of variation is: cv = S/x (averan) × 100. This value is usually used to indicate the precision of the analysis test results.

4. The calculation formula is as follows: the estimated standard error is an indicator of the relative deviation between the actual value and its estimated value, which is mainly used to measure the representativeness of the regression equation.

5. The standard deviation calculation formula is S=Sqr (∑(xn-x dial)^2/(n-1) In the formula, ∑ represents the sum, x dial represents the arithmetic average of x, ^2 represents the quadratic square, and Sqr represents the square root. Standard deviation is a statistical term.

6. The calculation formula for the standard error is that the standard error is equal to the root sign of the standard deviation divided by N.

Definition and calculation of error

System error: is the error caused by measuring instruments, tools, fixtures, etc. Accidental error: It is an accidental error caused by the operator's operation (or external factors). It only represents my personal opinion. If you don't like it, don't comment. Thank you.

The calculation formula is: error = (the largest absolute error) / range x100%.Error is the measured value minus the reference value. The measured value is referred to as the measured value, which represents the measured value of the measurement result. The so-called reference quantity value is generally expressed by the true value of the quantity or the agreed quantity value.

According to the definition, absolute error and relative error are converted into formulas: absolute error = | measured value - real value |; relative error = | measured value - real value |/real value. It can be seen from the formula that the absolute error represents the absolute value of the difference between the measured value and the real value, and the percentage of the real value accounted for by the relative error.