intro to probabilities Flashcards
probability
numerical measure of liklihood event will occur
probability eq
number of favorable outcomes/# of total outcomes
combination
allows one to count number of experimental outcomes when experiment involves selecting n objects from set of N objects
combination rule formula
N!/n!(N-n)!
is order neccessary for counting rule for permutation
yes
counting rule for permutation objective
count n objects from a set of N objects when order of selection is important
can numbers be repeated for counting rule for permutation with replacement
yes
can numbers be repeated for counting rule for permutation without replacement
no
two types of counting rule for permutation
with and without replacement
with replacement formula
N^n
counting rule for permutation without replacement formula
N!/(N-n)!
multiplication principle
sequence of K steps with n1 possible outcomes in 1st step and n2 in second step
does first step impact the second with multiplcation ruke
no
does first step impact the second with addition principle
yes
addition principle is
if 2 events E1 and E2 can occur indenpendently in m and n ways, then either of two events can occur in (m+n) ways
probbaility assigned to each experimental outcome must be between what
0-1
sum of all probabilities for all experimental outcomes is
1
pairwise mutually
in logic and prob theory two events are mutually exclusive or disjoint if they can not both occur at same time
what are the three method of assigning probabilities
classical, relative freq, ad subjective
classical method
approproate when all outcomes are equally likely
-if n outcomes are possible, then probability of 1/n is assigned to each outcome
relative freq method
appropriate when data is available to estimate the proportion of time the outcome will occur if the experiment is repeated a large # of times
subjective method
appropriate when one cannot realistically assume exp outcomes are equally likely and when little relevant data is available
what generates probability
repeated observations and theory
set theory
-compound events: union and intersection
-mutually exclusive evenys
-complement
compliment of A
the event consisting of all sample points not in A
union of 2 events
the union of A and B is venet containing all sample points belonging to A or B or both
intersection of A and B
the event containing sample points belonging to both A and B
know addition law for mutually exclusive events
yes
know addition law for non mutually exclusive events
yes
mutually exclusive events
two events are said to be mutually exclusive if events have no sample points in common
