
 Statistics Glossary  Probability 
  Discrete case : When a die is thrown, each of the possible faces 1,2,3,4,5,6  the xi's  has a probability of 1/6  the p(xi)'s  of showing. 
  A discrete random variable is one which may take on only a countable number of distinct values such as 0,1,2,3,4,........ 
  Typically, a Geometric random variable is the number of trials required to obtain the first failure, for example, the number of tosses of a coin untill the first 'tail' is obtained; components from a production line are tested, in turn, until the first defective item is found. 
 www.cas.lancs.ac.uk /glossary_v1.1/prob.html (3540 words) 
