Question

The total uncertainty in the average value of many measurements can be calculated as?

a) add individual uncertainties to the average value
b) subtract individual uncertainties from average value
c) add mean of individual uncertainties to average value
d) subtract mean of individual uncertainties to average value

Answer 1

b)

Explanation:

b) is the closest answer but it is only half of the story.

The uncertainty (well, should be called deviation for the average) is a measure of how far away is an individual measurement from the average, hence the subtraction.

The other half of the story is to estimate the average of all these deviations. This is done by taking the average of the absolute value of all the deviations or perform a standard deviation calculation .

The standard practice is to compute the standard deviation.