- Find the binomial probability:
P(25 < B(45, 0.2) < 35)
And it comes out as error. Can someone please tell me what I'm doing wrong.
In a new sheet, enter the numbers 0 throughn = 30 in column A. Type 0 in A1, 1
in A2 and 2 in A3, then highlight the three cells, and drag the small square in the
bottom right corner until cell A31 which should read 30. In cell B1 calculate P(X = 0)
where X is a binomial random variable with n = 30 and p = 0.4 . Use the command
=BINOMDIST(A1,30,0.4,FALSE). Copy down to cell B31.
Can someone please explain to me what I do in cell B1? Like what exactly am I supposed to type?
What makes you think that that is wrong?
The mean number of successes in 45 trials with p=0.2 is 9, 25 is a long way above 9, so far in fact that for most purposes the cumulative probability of 25 or fewer successes is indistinguishable from 1.
(Note BINOMDIS runs out of prescission before you get to 34 triaks in this case, and the cumulative returned is greater than 1, but that should not metter)
P(25 < B(45, 0.2) < 35)=Q(34)-Q(25)
where Q denote the cumulative distribution, not:
P(25 < B(45, 0.2) < 35)=Q(34)-Q(26)
which is what you have.