what is probalitly
a number between 0 and 1 measuirnng the likeleyhood that some event will occur
whats a random experiement
a procee that can lead to two or more outcomes wihtout knowing wht outce will occur
what are the specified outcomes that come out of random experiemnts knwon as
basic outcomes
what is aset of basic outocmes called. what symbol is used for it?
a sample space.
Ω
basic outcomes must be deifned so that they are…
mutually exclusive
collectivley exhaustive
what does mutally exclusive mean?
no two outcomes can occur simulataniously in a single experiment performance
what does collectivley exhaustive mean?
every performance of a rnaodm epxeriemnt must result in exaclty one of the basic outcomes
what is an event?whats is it shown as in an equation?
a subset of basic outcomes yeilding the same result
E
what is a null event?
its the absensce of a baisc outocme
what are the three kinds of event
indpendent, dependent, mutually exlcusive
whatd an independent event. example?
each event isnt affetced by oher events.
where re-doing and experiment will always have the same probablitly
what is a dependent event. example?
aka conditonal event
an event if affected by othewr events.
continuosly doing an experiment will change the proabilty of outcomes
whats a mutaully exclusive event. example?
events that cant occur at the smae time
fliping a coin, heads and tails are mutually exlusive
what is a random vairable
a random vairable is the numerical value you give to probabilties when calulating probablilty
what is a discrete random vairable
its a random vairable that takes on a countable number of values (finite)
whats a continuous random variable
where there is an infinte possible outcomes so no numerical value can be assinged
what does the probabilty mass function calculate
PMF calculates the probabilty that a discrete random variable will take on the value of one of its possible values
why can a probabilty only be between 0 and 1
probability cannot be negative nor can it exceed 100% (1)
what is cummulative distribution function? example to expalin?
CDF is the probability that X doesnt exceed a chosen value.
probailty of rolling 3 on a dice is 50% because the total probability of rolling the previous numbers adds up to 50%
what is the expected value of a random variable?
the expected value is essentially the average or mean of the probabilities within a ste of probabilities
how would you calculate the expcedt value of a random variable using the mean?
calculating the average possibility
times each value x by its probaility and add them together to find the average possibilty
