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Benjamin Irwin
If I have a result that can only be quoted to 2s.f., let's say 20, and I calculate an uncertainty of 0.2, then how do I quote this?
Benjamin Irwin said:If I have a result that can only be quoted to 2s.f., let's say 20, and I calculate an uncertainty of 0.2,
Significant figures are the digits in a number that represent the precision of a measurement. They are important because they indicate the level of uncertainty in a measurement and are used to determine the accuracy of a calculation or measurement.
The number of significant figures in a measurement is determined by counting all the digits in the measurement, including any zeros that are between non-zero digits. All non-zero digits are significant, and any zeros at the end of a decimal number or between non-zero digits are also significant. Any zeros at the beginning of a decimal number are not considered significant figures.
When performing calculations with significant figures, the result should be rounded to the same number of significant figures as the measurement with the least number of significant figures. If the final digit is 5 or higher, the preceding digit should be rounded up. If the final digit is 4 or lower, the preceding digit should be left unchanged.
Precision refers to the level of detail in a measurement, while accuracy refers to how close a measurement is to the true value. A measurement can be precise but not accurate, meaning that it has a small margin of error but is still far from the actual value. On the other hand, a measurement can be accurate but not precise, meaning that it is close to the true value but may have a larger margin of error.
Uncertainties refer to the possible range of values that a measurement can fall within, due to limitations in the measurement instrument or process. The larger the uncertainty, the less reliable the measurement is considered to be. It is important to consider and report uncertainties when presenting scientific data, as it helps to accurately represent the precision and accuracy of the measurement.