You would like to determine the percentage of coffee drinkers in your university, and collected the following binary data set from random students on campus, 1 for coffee drinker and 0 for otherwise: 0,0,0,1,1,0,1,0,1,1,1,1,0,0,0,1,0,1 ,0,0,0,0,0,1.
Let Yi denote the i 'th number in this list. You decide to model this data set under the following assumptions: Y1,…,Yn are identically distributed as some random variable Y. Y1,…,Yn are independent. Yi only takes the value 0 or 1 .
Under these assumptions, how many unknowns are needed to specify the distribution of Y ?