Concept explainers
You set out to determine the density of lead in the laboratory. Using a top loading balance to determine the mass and the water displacement method (Study Question 41) to determine the volume of a variety of pieces of lead, you calculate the following densities: 11.6 g/cm3, 11.8 g/cm3, 11.5 g/cm3, and 12.0 g/cm3. You consult a reference book and find that the accepted value for the density of lead is 11.3 g/cm3. Calculate your average value, percent error, and standard deviation of your results.
Interpretation: The average, percent error and standard deviation has to be calculated.
Concept introduction:
Precision: Is a measurement indicates how well several determination of the same quantity agree.
Accuracy: Is the agreement of a measurement with the accepted value of the quantity.
Percent error: The difference between measured result and the accepted value.
Answer to Problem 62RGQ
The average value is
The percent error obtained is
The obtained Standard deviation is
The average value, percent error and standard deviation is calculated as,
Explanation of Solution
Average density Value:
Hence, the average density value is obtained as shown above. Hence, the average value is
Percent error:
From the above calculation, the percent error is obtained as shown above.
Standard deviation:
The obtained Standard deviation is
The average value was calculated as
The percent error obtained was calculated as
The obtained Standard deviation was calculated as
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