Edward C. answered • 03/29/15

Caltech Grad for math tutoring: Algebra through Calculus

Pr[A|B] = Pr[AnB] / Pr[B] = 0.1 / 0.35 = 10/35 = 2/7 ~ 0.2857

Pr[B|A] = Pr[BnA] / Pr[A] = 0.1 / 0.4 = 0.25

Edward C.

tutor

Sorry maybe I did not understand your question. (1) asks for the conditional probability of A given that B has occurred. Since B has occurred the original sample space S is restricted to B, which occurs with probability 0.35. Within the space of B,
A occurs with probability 0.1 since the probability of A and B both occurring is 0.1. So the probability of A given B is 0.1 / 0.35 = 10 / 35 = 2/7. (2) is solved in a similar way.

Report

03/30/15

Katie C.

it was right I was just entering it into the wrong problem. Sorry, Thanks!!

Report

03/30/15

Katie C.

could you help me with other problems?

Suppose for this problem that Pr[E] = [ 5/8] and Pr[F] = [ 3/4]. Just as in the book, Pr[(E ∪F)′] = 0.

(1) What is Pr[E | F]?

(2) What is Pr[F | E]?

(1) What is Pr[E | F]?

(2) What is Pr[F | E]?

Suppose for this problem that Pr[E] = [ 1/12], Pr[F] = [ 1/6], and Pr[E ∩F′] = [ 0/1].

(1) What is Pr[E | F]?

(2) What is Pr[F | E]?

(1) What is Pr[E | F]?

(2) What is Pr[F | E]?

assume that Pr[E] = 0.3, Pr[F] = 0.35, and Pr[E′∩ F] = 0.15.

Compute the following conditional probabilities:

(1) Pr[E | F] =

(2) Pr[F | E] =

Compute the following conditional probabilities:

(1) Pr[E | F] =

(2) Pr[F | E] =

Report

03/30/15

Katie C.

03/30/15