I have collected a sample of 5000 wheat cent pennies, and recorded the number of each year and mint mark $\in \{P, D, S\}$. I have also found out how many wheat cent pennies were minted at each mint, during each year.
What would the formula be to determine if I have more of the common coins - the less valuable (i.e. more of that coin was minted) than would be expected, based on the number minted of one year & mint mark / total of all wheat cents minted?
Would it just be a straight independent probability of each coin based on sample size of 5000?