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Advanced Math Topics. 5.3 Conditional Probability. Notes. With Conditional Probability , the probability of an event changes on what has happened in previous events. p(A | B). = probability of A given that B has happened. p(A and B). p(A | B) =. p(B).
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Advanced Math Topics 5.3 Conditional Probability
Notes With Conditional Probability, the probability of an event changes on what has happened in previous events. p(A | B) = probability of A given that B has happened p(A and B) p(A | B)= p(B) We can analyze why this is the formula…
There are 2 green, 2 blue, and 2 red marbles in a bag. You selected 2 marbles Find p(picking a blue and a green). p(blue) x p(green | blue) p(blue & green) = Rearrange this formula to isolate p(green I blue): 2/6 x 2/5 p(blue & green) = = 4/30 = 2/15 p(blue) x p(green | blue) p(blue & green) = p(blue) p(blue) p(blue & green) = p(green | blue) p(blue) p(blue & green) p(green | blue) = p(blue) The conclusion… p(A & B) p(A | B) = p(B)
From the HW P. 256 2) 72% of all hospitalized senior citizen patients have medical insurance. The records indicate that 32% of all patients are females and have medical insurance. If a patient is selected at random, what is the probability that the patient is a female given that the patient has medical insurance? p(A & B) p(A | B) = p(B) p(female & insur.) p(female | insurance) = p(insur.) .32 p(female | insurance) = .72 44.44% p(female | insurance) =
From the HW P. 256 4) It was found that that 22% of females between the age of 20-30 years jog to stay in shape. 12% of the females jog and exercise at a health spa. If a female between the age of 20 to 30 years who is jogging is randomly selected, what is the probability that she exercises at a health spa? p(A & B) p(A | B) = p(B) p(spa & jog) p(spa | jog) = p(jog) .12 p(spa | jog) = .22 54.55% p(spa | jog) =
From the HW P. 256 11) On the board together.
HW P. 256 #2-11