Probability

Question 1

Probability

Answer 1

of ways an event can happen / # of possible outcomes

How likely or unlikely an event is to happen
closer to 0=unlikely
closer to 1=likely
#sucess :# of total outcomes ( Success + Failures)

Question 2

Conditional probabilities

Answer 2

Probabilty of A occuring if B has already happened
P(A If B)

Question 3

Marginal probability

Answer 3

Probability of a single event P(Heart attack)

Question 4

union

Answer 4

one event happens or another event happens
p( A or B)

Question 5

intersection

Answer 5

both happen at the same time
P(A and B)

Question 6

complements

Answer 6

event does not happen
P(not A )

Question 7

disjointed events

Answer 7

events that cannot both happen
-Ex: Heart attack and no heart attack

Question 8

complement

Answer 8

P ( not A )
1- P(A)

Question 9

additive rule

Answer 9

P( A or B) = P(A) +P(B) - P(A and B)

Question 10

multiplicative rule

Answer 10

P (A And B)= P (A if B) X P (B) =
P ( B if A) * P(A)
A and B are independent: P (A and B)= P(A) * P(B)

Question 11

conditional probabilities

Answer 11

Probanility of A occuring if B occured
P ( A if B)= P(A and B)/ P (B)

Question 12

independence

Answer 12

When one event happening does not affect another
P(A∩B)=P(A)×P(B)

Question 13

odds ( Calculating)

Answer 13

success : # failure

Question 14

Odds interpret

Answer 14

Odds of 3:1 mean that for every 3 favorable outcomes, there is 1 unfavorable outcome.

So, a favorable outcome is 3 times more likely than an unfavorable one.

Question 15

odds association

Answer 15

OR =1 implies no association
odds of the event occurring in one group are the same as the odds of the event occurring in the other group