Math 300 , Spring 2008, Mon. Jan. 28, Day 1 Hit reload to get most current version

Reading:  Ash, Intro and Sec. 1-1.  Please read Ahead, Sec. 1-2&3 
       (Review: Moore & McCabe, 4.2.  (for day 1, to independence , p.294 4th ed., p. 266 5th ed.)


HW: A)  Ash, p. 6, #3 thru 9 (give answers and draw sets of outcomes on handout for 2 dice)
    B) Find the probability distribution of the sum of the 2 dice (i.e. for every possible value that the sum can take on, give its probability.)  Arrange the values in a table
sum    | 2   3   4      ...       12
Prob  |

In class: Go over syllabus.   Please return Questionnaire as soon as you can.
Notes are a brief  overview of the material, not a substitute for the book.  Notes may also include things not in the book.

Chance Experiment:  Sample space S, events A, probability P(A).
Probability Axioms:  Simple: S,  P(A), probability of events A assigned for every A
    0< P(A) < 1; 
P(S)=1
    P(Not A) = 1-P(A)  (Not A is the complement of A; all the outcomes Not described by A. Ac or A with a bar.)
    Discrete space: P(A) = sum of probabilities of all outcomes in A
Equally likely space: P(A) = (# of outcomes favorable to A) /(total # of outcomes)

Axioms (mathematical model:  mid 20th century)  common to all  Interpretations (applied to "real world")
       1) "Classical" =  n "equally likely outcomes", prob of each is 1/n.  (Get a lot of mileage from this.)
                 but many situations don't have equally likely outcomes
       
2) "Frequentist" = "empirical" , P(A) = proportion (relative frequency) of times A would occur in a very long series of repetitions of the experiment.
                but many experiments can't be repeated a very many times...
        3) "Subjective" = "personal" = "Bayesian",  P(A) is MY assignment.  (Betting on the horses.  Stockmarket.)
    If you have a lot of data (i.e. enough for the Frequentist) then for a particular experiment, all of the interpretations will give about the same probability distribution  (Bayesians are not stupid; will use evidence.) .
We'll use the Classical method to build a lot of probability models; our underlying philosophy is Frequentist.  We'll learn "Bayes' Theorem" which Bayesians use to alter personal probabilities when they get new evidence.


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