I have some mortality data and I am trying to determine if the mortality is different in one subpopulation compared to the total population. The problem is I am having trouble determining which statistical tests to run.
Say I am comparing the number of deaths due to murder in these two populations in a single year. I have estimated the deaths due to murder in the subpopulation in this year based on a 10 year average (which is why it is a decimal <1).
Farmers All occupations Murders 0.4 30 Total population 2800 8000000
I can calculate the murder rate per 100,000 people which is 14.3 for farmers and 0.38 for the general population. I can calculate the expected number of farmer murders based on the general population rate, which would be 0.01 murders. I can calculate ratios of the murder rates (14.3/0.38 = 37.6) or observed and expected rates.
I know this is really quite basic but I'm a novice at this and struggling. I am unsure if it is more meaningful to compare crude murder rates or calculate the rate ratio. How can I calculate a p-value and 95% confidence interval to determine whether the rate difference or rate ratio is statistically significant?