a random sample of 100 voters were selected. 30 favored candidate A, 38 favored candidate B, 21 favored candidate C. find the max likelihood estimate for the proportions of votes favoring candidate A,B,C. also, estimate the diff btw the fractions favoring A and B and place a 2 std dev bound on the error of estimation.

what is the prob density for this function? and how do i found the std dev for the second part?

thank you