How to get the Uncertainty of a percentage change

[usehn]

Homework Statement

to get uncertainty of percentage change

Relevant Equations

((a-b)/b)*100

I have a measurement with uncertainties for two years. Say
Year 1 Rain : 100mm(80-120mm)
Year 2 Rain : 120mm(103-131mm).

Now I get the percentage change in rain in Year 2 w.r.t Year 1 as 20%. Is there a way to get the uncertainty associated with this percentage change?

 

[phinds]

I have a measurement with uncertainties for two years. Say
Year 1 Rain : 100mm(80-120mm)
Year 2 Rain : 120mm(103-131mm).

Now I get the percentage change in rain in Year 2 w.r.t Year 1 as 20%. Is there a way to get the uncertainty associated with this percentage change?

What is the maximum difference of possible set of values above 20mm and below 20mm. What are those relative to 20mm?

 

[usehn]

great thank you! Got it

 

[phinds]

Well, some folks misunderstand how to do that so it would be a good idea to post your conclusions / answer

 

[William Crawford]

Have you tried propagation of error?