NEGBINOMDIST function

Returns the negative binomial distribution


 * NEGBINOMDIST(number_f,number_s,probability_s)
 * Number_f - the number of failures.
 * Number_s - the threshold number of successes.
 * Probability_s - the probability of a success.
 * Number_f and number_s are truncated to integers.
 * If any argument is nonnumeric, NEGBINOMDIST returns the #VALUE! error value.
 * If probability_s 1, NEGBINOMDIST returns the #NUM! error value.
 * If number_f < 0 or number_s < 1, NEGBINOMDIST returns the #NUM! error value.