On 09/11/2013 08:37 PM, [email protected] wrote: > We have a sample which comes from a binomial process with unknown > probability. Is it possible to get the likelihood of the population is larger > than a user-specified value (with e.g. 95% certainty) in commons-math? > For example, given we have two samples: > S1: we have 4 out of 5 successes > S2: we have 80 out of 100 successes > > I would like to know the probability that the real mean is larger than 60% > given one of the samples above. Is there an easy way to calculate it?
Hi Thorsten, there is not yet a binomial test available (would be a nice addition), but you can calculate the requested values with the binomial distribution: // create a binomial distribution with null hypothesis of p=0.6 BinomialDistribution s1 = new BinomialDistribution(5, 0.6); System.out.println(1 - s1.cumulativeProbability(4-1)); // = 0.3369 > 0.05 significance level // thus null hypothesis can not be rejected BinomialDistribution s2 = new BinomialDistribution(100, 0.6); System.out.println(1 - s2.cumulativeProbability(80-1)); // = 1.64e-5 < 0.05 significance level // thus null hypothesis can be rejected // the observed probability must be larger Note: the - 1 is used to get the same results as with R binom.test see also http://stats.stackexchange.com/questions/44125/is-there-an-error-in-the-one-sided-binomial-test-in-r Best regards, Thomas --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
