What is the probability of B if they are independent events P(A)= 3/7, P(A then B)=1/3?

↳Redirected from "Suppose that I don't have a formula for #g(x)# but I know that #g(1) = 3# and #g'(x) = sqrt(x^2+15)# for all x. How do I use a linear approximation to estimate #g(0.9)# and #g(1.1)#?"
2 Answers
NGBRO
Apr 2, 2017

#7/9#

Explanation:

#P(A->B)=P(A)*P(B)#

#1/3=3/7*P(B)#

#P(B)=(1/3)/(3/7)=7/9#

Ratnaker Mehta
Apr 2, 2017

#P(B)=1/3.#

Explanation:

A Clarification : I interpret #P(A" then "B) as, P(B/A)#, i.e., the

Cond. Prob. of an event #B,# knowing that the event #A# has

already occurred.

So, if the events #A and B# are independent,

#P(B/A)=P(B)=1/3.#

In an otherway round, if we define, Independence of events

#A and B iff P(AnnB)=P(A)*P(B),# we get the same reult as follows:

#P(A" then "B)=P(B/A)=(P(BnnA))/(P(A))={P(B)*P(A)}/(P(A))=P(B).#

Enjoy Maths.!

Related questions
See all questions in Theoretical and Experimental Probability
Impact of this question
3478 views around the world
You can reuse this answer
Creative Commons License