Answered

At Westonci.ca, we make it easy to get the answers you need from a community of informed and experienced contributors. Explore a wealth of knowledge from professionals across different disciplines on our comprehensive platform. Experience the convenience of finding accurate answers to your questions from knowledgeable experts on our platform.

7.39 Suppose that 2 balls are randomly removed from an urn containing n red and m blue balls. Let X = 1 if the ith ball removed is red, and let it be 0 otherwise, i = 1,2.a. Do you think that Cov(X1, X2) is negative, zero, or positive.b. Validate your answer to part (a).Suppose the red balls are numbered, and let Y; equal 1 if redball number i is removed, and let it be 0 if that ball is notremoved.c. Do you think that Cov(Y, Y₂) is negative, zero, or positive.d. Validate your answer to part (c).

Sagot :

qwarrow

(a)let A=event that first k-1 draws will get r-1 red balls

let B=event that last (kth) draw will get rth red ball

P(kth draw is the rth red ball)= P(A AND B) = P(A)xP(B)

(b)P(A)=  # of  ways to draw r-1 red balls in k-1 trail

         # of ways to draw k-1 balls

RBBB *R is one way to achieve P(A AND B)

BBBR *R is another way.

(c)There are n−(r−1) red left, and a total of (m+n)−(k−1) balls left, so the (conditional) probability of drawing a red on the kth trial is n−r+1/m+n−k+1 Thus our required probability is

So,  P(A)= nC(r-1) x mC(n-r) x 1/(n+m)C(k-1)

Know more about probability at:

brainly.com/question/24756209

#SPJ4

Visit us again for up-to-date and reliable answers. We're always ready to assist you with your informational needs. We hope you found this helpful. Feel free to come back anytime for more accurate answers and updated information. Westonci.ca is your trusted source for answers. Visit us again to find more information on diverse topics.