STAT 202: Quantitative Methods for Scientific Research
Conditional probability
term
equation for two Pr - answers✔✔A "given" B
Pr(A|B)=Pr(AB)/Pr(B)
What is Pr A given B if both events are independant - answers✔✔Pr(A|B)=Pr(A)
since B doesn't affect A
partition rule - answers✔✔P(A) = P(A∩B) + P(A∩-B)
How to make a tree diagram - answers✔✔Pr(A) and Pr(-A)
Pr(B|A) and Pr(-B|A)
(same for Pr(-A))
Now mutliply Pr and you have Pr(AB) and Pr(A-B) and so on
term "or" - answers✔✔Indicated overlap between probabilities
Pr(MUP)=Pr(M)+Pr(P)-Pr(MP)
, Sampling with and without replacement - answers✔✔When we sample with replacement, the
two sample values are independent. Practically, this means that what we get on the first one
doesn't affect what we get on the second. Mathematically, this means that the covariance
between the two is zero. In sampling without replacement, the two sample values aren't
independent.
if something is sampled with replacement, how does it work with Pr? - answers✔✔Use same Pr
twice.
Eg. flipping a coin
Pr(flip1)*Pr(flip2)
what does factorial indicate? - answers✔✔number of ways to arrange distinct objects
n choose x - answers✔✔n!/x!(n-x)!
number of ways x objects can be selected from n objects
3 choose 2 = 3
letters in BIO
BO
IO
OB
what are the uses of a choose function? - answers✔✔number of ways x objects can be selected
from n objects
also:
Conditional probability
term
equation for two Pr - answers✔✔A "given" B
Pr(A|B)=Pr(AB)/Pr(B)
What is Pr A given B if both events are independant - answers✔✔Pr(A|B)=Pr(A)
since B doesn't affect A
partition rule - answers✔✔P(A) = P(A∩B) + P(A∩-B)
How to make a tree diagram - answers✔✔Pr(A) and Pr(-A)
Pr(B|A) and Pr(-B|A)
(same for Pr(-A))
Now mutliply Pr and you have Pr(AB) and Pr(A-B) and so on
term "or" - answers✔✔Indicated overlap between probabilities
Pr(MUP)=Pr(M)+Pr(P)-Pr(MP)
, Sampling with and without replacement - answers✔✔When we sample with replacement, the
two sample values are independent. Practically, this means that what we get on the first one
doesn't affect what we get on the second. Mathematically, this means that the covariance
between the two is zero. In sampling without replacement, the two sample values aren't
independent.
if something is sampled with replacement, how does it work with Pr? - answers✔✔Use same Pr
twice.
Eg. flipping a coin
Pr(flip1)*Pr(flip2)
what does factorial indicate? - answers✔✔number of ways to arrange distinct objects
n choose x - answers✔✔n!/x!(n-x)!
number of ways x objects can be selected from n objects
3 choose 2 = 3
letters in BIO
BO
IO
OB
what are the uses of a choose function? - answers✔✔number of ways x objects can be selected
from n objects
also:
