Binomdist

[tedcahill2]

I'm working on a probability model in Excel and I'm trying to use the BINOMDIST function but I'm running into an issue with the results.

Here's my function BINOMDIST(1,2,1/3,FALSE), the result I get is .4444. I agree with the result but it isn't what I'm looking for. The function as written, and thus the result, is giving me the probability of having exactly 1 success.

I want to know the probability of having at least 1 success. So I attempted to use BINOMDIST(>1,2,1/3,FALSE) but the function doesn't work with the > symbol in there.

Any thoughts?

[joeu2004]

Binomdist(1,2,1/3,true)

[shg]

Binomdist(1, 2, 1/3, true) ~ 89% gives the probability of having at most 1 success, i.e., 0 or 1.

The probability of at least 1 success is

1 - Binomdist(0, 2, 1/3, true) ~ 56%

[tedcahill2]

Binomdist(1, 2, 1/3, true) ~ 89% gives the probability of having at most 1 success, i.e., 0 or 1.

The probability of at least 1 success is

1 - Binomdist(0, 2, 1/3, true) ~ 56%

Yes this works, but I still can't seem to figure out how to apply this to other probabilities for some reason.

For example, I also want to figure out the odds of getting 2 successes in 2 tests with 1/3 odds, which I believe is ~11% but I can't write the function correctly to calculate it.

EDIT: I think I got it 1-BINOMDIST(s-1,tests,1/3,TRUE) seems to work

[shg]

I also want to figure out the odds of getting 2 successes in 2 tests with 1/3 odds ...

=BinomDist(2, 2, 1/3, false)