MTB > # selecting a beta prior
MTB > # by statements about the predictive distribution
MTB > #
MTB > # baseball example:  suppose I think that the probability
MTB > # a player will get a hit is .3; if the player does get a
MTB > # hit, I think the probability he will get a 2nd hit is .31
MTB > 
MTB > exec 'beta_sel'
 
What is the probability of a success on the first trial?
 
DATA> .3
 
If the first trial is a success, what is the conditional probability
of a success on the second trial?
(This should be larger than the first number you gave.)
 
DATA> .31
 
The matching values of the beta parameters a and b corresponding
to your predictive probabilities are given by:

 Row      a      b

   1   20.7   48.3