L3 - Probability Flashcards
what is a random event?
an event that is unpredictable, we can calculate the probability of such events occurring
what does P(x) represent? and what values does it produce?
P(x) = probability. it produces values between 0 and 1 that can be written as a percentage
what does a probability of 0 mean?
the outcome will never happen
what does a probability of 1 mean?
The outcome will occur.
NOTE: probabilities of all outcomes must add up to 1
what is an experiment in the context of statistics?
a process that, when preformed, results in one of many possible outcomes of the experiment. The collection of outcomes is called the sample space.
what are the three types of probability?
Subjective, Theoretical, Experimental
what is subjective probability?
based on experience and intuition, an opinion
What is Theoretical Probability?
It is based on knowing all the equally likely outcomes of an experiment
p(event) = # of favourable outcomes / Total # of outcomes possible
What is Experimental probability?
It is based upon repetitions of an actual experiment - relative frequencies. only applies to events that can be repeated over and over again.
P(event) = # of favourable outcomes / total number of trials.
What are independent events?
if two events occur and the outcomes of one can in NO way influence the outcome of the other.
eg. flipping a coin twice.
what are mutually exclusive events
two events that can’t occur at the same time.
eg. its impossible to flip a coin and it land on both heads and tails.
what is random selection
each item within a sample has an equal probability to be chosen.
what is a permutation problem?
when different orderings of the same items are to be counted separately
eg. ordering book titles
what is a Combination problem?
when different orderings are not to be counted separately
provide an Example of a Subjective probability
Knowing what happens when you throw a ball in the air for the first time.
