- #1
kelly0303
- 579
- 33
Hello! I have some counts measured at fixed points, both for background only and signal+background. Say that for a given x I have 16 counts with background only and 100 for background+signal. So the background is ##16\pm 4## and for the signal+background ##100\pm 10## (assuming poisson statistics). If I want to subtract the background, I get 84 counts. I am not sure what error to put on this number. If I use Poisson, I would have ##84 \pm \sqrt{84}##. If I use the error propagation for taking the difference I get an error of ##\sqrt{4^2+10^2}=\sqrt{116}## so I get ##84 \pm \sqrt{116}##. Which one of these is the right way?