additional 2 Flashcards
What is probability
a numerical measure of the likelihood that an event will occur
What can probability be used for
used as measures of the degree of uncertainty
probability values are always assigned on a scale of
0 to 1
what is a prob of near zero indicate
event is unlikely to occur
what is prob of near 1 indicate
an event is almost certain to occur
what is an experiment
a process that generates well-defined outcomes
what is a sample space
set of all experimental outcomes
what is an experimental outcome also called
a sample point
what is a sample point
identifies an element of the sample space
What is the counting rule for a multistep experiment
if an experiment can be described as a sequence of k steps with n1 possible outcomes on the first step, n2 possible outcomes on the second step, and so on
What is a tree diagram
a graphical representation that helps us visualize the multi-step experiment
In a tree diagram, along the branches you
multiply
What are the 3 useful Counting Rules
- Multistep experiment
- Combinations
- Permutations
What are combinations
- allows us to count the # of experimental outcomes when the experiment involves select n objects for a set of N objects and ORDER DOES NOT MATTER
What are permutations
- allows us to compute the # of experimental outcomes when n objects are to be selected from a set of N objects and ORDER MATTERS
Does permutations or combinations result in more
permutations
b/c every selection of n objects can be ordered in n! different ways
What are the 3 most useful approaches for assigning probabilities
- Classical Method
- Relative Frequency method
- Subjective method
Explain classical method
use when: all experimental outcome are EQUALLY LIKELY
- the 2 basic requirements are satisfied
- example tossing a coin
Explain when to use the Relative Freq. Method
use when: data re available to estimate PROPROTION Of TIME and the experimental outcome will occur if the experiment is REPEATED a LARGE # of TIMES
- 2 basic requirements are satisfied
Explain when you would use the Subjective Method
Use When: we CANNOT realistically assume that the experimental outcomes are Equally Likely and when Little relevant data is available - degree of belief
Which method would we use Bayes Theorem for
Subjective method
what are the basic requirements for assigning Probabilities
- the prob assigned to each experimental outcome must be b/w 0 and 1 inclusively
- Sum of prob for all experimental outcomes must equal 1.0
What is an event
collection of sample points
what is the prob of an event
equal to the sum of the prob(s) of the sample points in the event