{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Week3_Notes

# Week3_Notes - Psych 100A Week 3 Discussion Notes Dawn Chen...

This preview shows pages 1–2. Sign up to view the full content.

Psych 100A Week 3 Discussion Notes Dawn Chen October 16, 2009 Probability Terms Probability : How likely an event is to occur Outcome : One possible way something could happen; a result of a random experiment Sample space : The set of all possible outcomes (e.g., the sample space for flipping a coin twice is {HH, HT, TH, TT}) Event : A subset of the sample space (e.g., the event of getting at least one heads when tossing a coin twice is {HH, HT, TH}) Probability distribution : Divides the sample space into non-overlapping portions and assigns a probability to every portion Notation ( ) P A : Probability of the event A ( ) P A : Probability of A not occurring ( ) P A B : Probability of A or B occurring ( ) P A B : Probability of A and B occurring Properties 0 ( ) 1 P A Every probability distribution sums to 1. Formulas If every outcome is equally likely, # of outcomes in ( ) total # of outcomes A P A = If A and B are mutually exclusive, ( ) ( ) ( ) P A B P A P B = + If A and B are not mutually exclusive, ( ) ( ) ( ) ( ) P A B P A P B P A B = + - The Normal Distribution The normal distribution is a theoretical probability distribution that is useful because it approximates many distributions of real-world measures that are determined by a large number of factors, such as IQ. The normal distribution is symmetric , unimodal , and continuous . It extends infinitely to the left and right, always approaching 0 but never quite reaching 0.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}