Once a week a merchandiser replenishes the stocks of a particular product brand in the six stores for which she is responsible. Experience has shown that there is one in five chance that a given store will have run out of stock before the merchandiser's weekly visit. a) Which probability distribution is appropriate in this problem and why? b) What is the probability that, on a given weekly round, the merchandiser will find exactly one store out of stock? c)What is the probability that the most two stores will be out of stock? d) What is the mean number of stores out of stock each week?