Does Averaging Numbers Reduce Their Combined Uncertainty?

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Discussion Overview

The discussion centers around the concept of averaging numbers with associated uncertainties and how this affects the overall uncertainty of the average. Participants explore the mathematical treatment of uncertainties in the context of averaging, with a focus on whether the combined uncertainty is simply the sum of the absolute uncertainties or if a different approach is warranted.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions whether the average of three numbers with equal uncertainties results in an uncertainty equal to the sum of the absolute uncertainties of those numbers.
  • Another participant suggests taking the square root of the sum of the squares of the uncertainties, implying this might provide a different method for calculating the overall uncertainty.
  • A subsequent post seeks clarification on whether the square root method applies to the uncertainties themselves or the original numbers, indicating a need for further explanation on how this affects the uncertainty of the average.
  • It is clarified that the square root method pertains to the uncertainties, suggesting it yields the absolute uncertainty of the average.

Areas of Agreement / Disagreement

Participants express differing views on how to calculate the uncertainty of an average, with no consensus reached on the correct method. The discussion remains unresolved regarding the appropriate approach to combining uncertainties in this context.

Contextual Notes

Participants have not fully explored the implications of different methods for combining uncertainties, and there may be assumptions regarding the nature of the uncertainties that are not explicitly stated.

lapo3399
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If an average of three numbers with equal uncertainties is taken, does the average have an uncertainty of the sum of the absolute uncertainties of the three numbers?
e.g. (3.0 +/- 0.1) + (6.0 +/- 0.1) + (9.0 +/- 0.1)/3 = 6.0 +/- 0.3?
This makes sense to me because the three in the denominator has no uncertainty.

p.s. I know this may not seem like it belongs in this forum ( :confused: ), though uncertainties are scientific calculations, so...
 
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Take the square root of the sum of the squares of the values.
 
What values, the uncertainties or the numbers? What will that give me? The uncertainty?
 
The uncertainties, it's going to give you the absolute uncertainty.
 

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