I am trying to compare the proportions of two populations, using
My data is straightforward - first population is 6/26 and second is 15/171. I am trying to see if I have significance that the proportion in the first population is greater than the second.
When I run the
prop.test in R, my code is:
prop.test(c(6,15), c(26, 171), alternative="greater").
However, I get a warning:
In prop.test(c(6, 15), c(26, 171), alternative = "greater") : Chi-squared approximation may be incorrect
My assumption is that this is based on the small sample size in the first population. Is that correct? I have read this post, which seems to indicate that indeed the issue is small sample size, but the solution provided isn't applicable with the prop.test.
Is there any way to correct for this?
If there is not, is there any way to get a sense as to how much lack of correctness in the chi-squared approximation may be impacting on my p-value? In this case, the p-value reported is 0.03137. Can I assume that even with the potential issue with the chi-squared approximation I would still have 95% confidence, or not necessarily?