random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution random variable with gamma distribution