2019 Maths Standard 2 HSC Q8 Find absolute error of weight measurement 79.3 kg shown on scale

Source: © NSW Education Standards Authority

Disclaimer: This sample solution is intended as a guide only and does not necessarily represent the best way to answer the question, nor is there any guarantee of accuracy.
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The absolute error of a measurement, based on precision (or resolution), is typically half of the smallest measurement unit. In this case, we don't have information about the precision of the measurement instrument used to measure the person's weight.

If you know the precision or the smallest measurement unit of the instrument, you can use that to calculate the absolute error. For example, if the scale used to measure the person's weight is precise to the nearest 0.1 kg, then the absolute error would be half of that precision, which is 0.05 kg, or 50 grams.