We will rederive the negative binomial PMF as we did in clas

We will rederive the negative binomial PMF as we did in class. The probability of success if p and the number of successes we wish to find is r.

a)How many ways is there to get r-1 successes among x-1 trials?

b)What is the probability of getting r-1 successes and x-r failures in that order if successes and failures are independent? In detail

c)Use the answers in (a) and (b) to find the probability of getting r-1 successes in x-1 trials. In detail