Difference Between Accuracy And Precision.
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Difference Between Accuracy And Precision

Figure 7.1 (a) presents two data sets. Which of the data sets is more precise?

Figure 7.1 (b) presents the indirect measurement of the mass of sugar with a scale that always read 0.50 too low. A researcher obtains the mass of a beaker to be 50.62 g with the scale. Thereafter, she added some sugar to the beaker and obtain a total mass of 69.88 g using the same scale. The mass of sugar she calculated is 19.26 g. Is the error in the measurement of the mass of sugar 0.50 g?

The strings: S7P2A21 (Identity - Physical Property).

The math:
Pj Problem of Interest is of type Identity (physical property). Measurement seeks to identity the value of the entity being measured.

(a)Range (max value - min value) of data set 1 = 73.34 - 72.75 = 0.59
Range of data set 2 = 72.01 - 71.98 = 0.03
Data set 2 is more precise because it has the lower range.
Precision indicates how close a set of measurements are to one another, irrespective of whether the measurements are correct.

(b) Mass of beaker (error of scale taken into account) = (50.62 + 0.50) g
Mass of beaker plus sugar (error of scale taken into account) = (69.88 + 0.50) g
Mass of sugar = (50.62 + 0.50) - (69.88 + 0.50) = 19.26 g
Mass of sugar is not inaccurate by 0.50 because error of scale cancels out.
Accuracy indicates how close a measurement is to the true or correct value.

Blessed are they that have not seen, and yet have believed. John 20:29