what is accuracy and precision ? with example.


What is ACCURACY And PRECISION ?

ACCURACY : accuracy is the closeness between the measured value and accepted or true value of the measured quantity.
           The accurate value of the sample can be determined by averaging the precise value.
Eg :
 in a organic sample the percentage of carbon 49. 50 by the analysis off two analyst are as follows :-
  A --49. 40, 49. 47, 49.53, 49.64
  Mean = 49.51
  B -- 49.01, 49.03, 49.03, 49.04
  Mean = 49.03
Therefore, A is more accurate than B.


PRECISION : the agreement between a set of result made on same sample in an identical manner is known as precision of the measurement i.e., precision reflects the closeness among the replicate measurement of the same quantity.
Eg :
In an organic compound two analyst analysis as follows :-
A -- 49.40, 49.47, 49.53, 49.64
B -- 49.01, 49.03, 49.03, 49.04.
     In this analysis analyst B is more precise.

difference between accuracy and precision-

                                                  Accuracy                                                              Precision
  1. Accuracy is the closeness between the measured value and accepted or true value of the measured quantity.
The accurate value of the sample can be determined by averaging the precise value.
  1. The agreement between a set of result made on same sample in an identical manner is known as precision of the measurement i.e., precision reflects the closeness among the replicate measurement of the same quantity.
    2. It can be determine almost exactly by replicate measurement of same quantity.      2. It cannot be determine exactly.
    3. It is express in terms of deviation of mean.      3. It is express in terms of absolute and relative error.

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