Say I have a "large" population (larger than 1000) of red cards and blue cards which I want to find if it is evenly split (1:1 red:blue ratio). So I do an experiment and pull out 125 cards at random, and find that I have 50 red and 75 blue. Based on this experiment, what can I say about the red:blue ratio in the population? What is the "confidence" that the ratio is NOT 1:1? I'm unsure what "confidence" means here, I can find for example the probability of getting more than 75 blue cards out of 125 by using the normal approx. to the binomial distribution but I'm not sure what that says about the population. Can anyone give me some help on how to analyze this kind of data? How much information can we extract from this one experiment?