If the true value for a result is 2.00 g and a student takes 2 measure...
Precision indicates how closely repeated measurements match each other. Since both the values are close to each other, they are precise and since their is a difference between the mean value and true value, they are not accurate.
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If the true value for a result is 2.00 g and a student takes 2 measure...
Both experimental values are close to each other but are not close to true value.
If the true value for a result is 2.00 g and a student takes 2 measure...
Precision and Accuracy:
In the context of measurements, precision refers to the degree of agreement or reproducibility between individual measurements, while accuracy refers to the closeness of a measurement to the true value. Let's analyze the given measurements to determine their precision and accuracy.
Measurement 1:
The first measurement reported by the student is 1.95 g. Since the true value is 2.00 g, we can calculate the percent error as follows:
Percent Error = [(Measured Value - True Value) / True Value] * 100
= [(1.95 - 2.00) / 2.00] * 100
= (-0.05 / 2.00) * 100
= -2.5%
Measurement 2:
The second measurement reported by the student is 1.93 g. Again, we can calculate the percent error:
Percent Error = [(Measured Value - True Value) / True Value] * 100
= [(1.93 - 2.00) / 2.00] * 100
= (-0.07 / 2.00) * 100
= -3.5%
Precision:
To determine the precision, we examine the degree of agreement or reproducibility between the two measurements. In this case, the measurements differ by 0.02 g (1.95 g - 1.93 g), indicating that they are not identical. However, the difference between the measurements is quite small, suggesting a relatively high degree of precision.
Accuracy:
To assess accuracy, we compare the measurements to the true value. Both measurements are slightly lower than the true value (2.00 g), resulting in negative percent errors (-2.5% and -3.5%). These negative percent errors indicate that the measurements underestimate the true value.
Conclusion:
Given that the measurements are not identical but only differ by a small amount, we can conclude that they are precise. However, since the measurements underestimate the true value, they are not accurate. Therefore, the correct answer is option 'D': The values are precise.
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