Loading Means, Anomalies and Uncertainty…
Quick guide: plain English, key facts and method
In plain English: Repeating a measurement and taking the mean gives a better estimate of the true value. Anomalies are results that do not fit and are left out.
Key facts
- Mean = total of the values ÷ number of values.
- An anomalous result is one that does not fit the pattern of the others.
- Leave out anomalies when you work out the mean, and say that you have done so.
- Range = highest value − lowest value.
- Uncertainty ≈ ± half the range of the repeat readings.
- Repeating readings and calculating a mean reduces the effect of random errors.
How to do it
- Look along each row of repeats for one value far from the others.
- Add the remaining values and divide by how many there are.
- Give the mean to the same number of decimal places as the data.
- For uncertainty, find the range of the repeats and halve it.