Lec 3 Flashcards
what is the definition of probability?
Numerical measure of likelihood that an event will occur. The proportion of
times the event would occur if we repeated a random trial over and over, under
identical conditions
a pr[event] ranges from what to what?
0-1
what do probability distributions describe?
the probabilities of all mutually exclusive outcomes
what is the sample space of an experiment?
the set of all experimental outcomes
what does a discreet random variable assume?
they assume that the data has discreet values
what does a continuous random variable assume?
the data could have any value at an interval
the total area under the curve always sums to what?
10
the area under the curve describes what?
the probability that a randomly chosen variable falls within some range
to find the amount of different data sets you must take what equation?
N^K, N is the number of possible outcomes of each trial, and K is the number of trials
what is N!?
N! is the factorial of N e.g. (if n=5, N!= [12345])
what is the classical method for probability?
all outcomes are equally likely
what is the relative frequency method of probability?
based on observations?
what is the subjective frequency method?
based on frequencies
what is an event?
a collection of one or more sample points
P(event) is what?
the sum of probabilities of sample points at the event
what are mutually exclusive events?
events that cannot occur at the same time
the probabilities of all mutually exclusive events sum to what?
1
for mutually exclusive events their probabilities follow what rule?
the addition rule
what is the addition rule?
when accouting for mutually exclusive probabilities add both values
what is the general addition rule?
for non mutually exclusive events you add both values and then subtract the sum by the multiplied value of both values.
if events are both indipendant what rule do you follow?
the multiplication rule
what is the multiplication rule?
if two events are indipendant multiply their respective pr(values)
what is a dependant event?
an event where the data is analyzed provided that an event occured
