# What distribution describes this process?

I have three clinics that are testing for Zika virus. We know the proportion of positives aggregated across all clinics, i.e., the first clinic has identified 20% of all positives across the three clinics, the second 30% and the third 50%. Now we know there are 100 new cases but these proportions change with respect to previous cases, i.e., they are now 10% 50% and 40%. Is there a distribution that can tell me if these proportions are significantly different than would be expected given the original proportions? I have run a Monte Carlo simulation to figure this out, but I was wondering if there was a distribution that describes this.

• If you know nothing about the volumes, then you can't simulate this with Monte Carlo either. Jun 27 '16 at 18:05
• Thanks for you comment. However, I think if we make an assumption that the relative volumes are constant it is ok.
– jtam
Jun 27 '16 at 20:56
• It's not enough. You'd need an assumption of what are these relative volumes. Jun 27 '16 at 21:10
• Indeed. I can do this with another assumption: that the relative volume of patients is equal to the relative number of positives.
– jtam
Jun 27 '16 at 21:15
• So, maybe you can add these assumptions to your question, then it'll be more realistic to come up with the distribution. Otherwise your question has too many degrees of freedom to suggest a sensible answer. Jun 27 '16 at 21:19