howeveras you get between two and three standard deviations (- to - and to )we're down to just little bit over ( %to be preciseas you get out beyond three standard deviations (- and sthen we're much less than sothe graph is just way to visualize and talk about the probabilities of the given data point happening againa probability distribution function gives you the probability of data point falling within some given range of given valueand normal function is just one example of probability density function we'll look at some more in moment probability mass functions now when you're dealing with discrete datathat little nuance about having infinite numbers of possible values goes awayand we call that something different so that is probability mass function if you're dealing with discrete datayou can talk about probability mass functions here' graph to help visualize this