00:01
So for part a here, to find the probability of approve, approve, disapprove, assuming that each individual result is independent, this would be equal to the probability of approval times the probability of approval, times the probability of disapproval.
00:23
So plugging in our values, we have that probability of approve is 0 .61.
00:28
So we have 0 .61 times 0 .61, times probability of disapproval, which is 0 .35.
00:35
So we get a result of roughly 0 .1302.
00:43
Then, for part b, let's see here, the probability that exactly two of the three approve and one disapproves, so probability of if x is equal to the number of people who disapprove, okay, actually, treating this as, i was going to treat this as a binomial, that's not quite appropriate, but saying it's probability of 2a, d, we can think of that as being probability of approve, approve, disapprove, plus probability of approve, disapprove, approve, plus the probability of disapprove, approve, approve...