Notes 7 - Notes 7 Random Variables A random variable (r.v.)...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Notes 7 Random Variables A random variable (r.v.) is a function whose values are 1) numerical and 2) depend on the outcomes of a random process. Simply put , a random variable is a quantity whose value depends on chance. &ote : We usually use a capital letter to denote the random variable itself and the corresponding common letter to represent the value which the variable takes. Eg. Y = y A random variable assumes exactly one numerical value for each outcome of the random process. The SAMPLE SPACE (S) of a random variable is the set of all possible values that the random variable can take. Examples: X= the number of people who have been to a movie V = the liquid volume of soda in a can marked 12 oz. A discrete random variable has a finite or countable number of possible values. i.e. the sample space consists of a finite number of values (or an infinite number of values that are countable). Example: Three people are chosen at random and asked if they have seen the movie "Bourne Ultimatum". Define the r.v. : Let X = the number of people (out of the 3) who have seen the Bourne Ultimatum (i.e. the yes answers) Sample Space : S = {0, 1, 2, 3} (These are all the possible values that X can take) The sample space is finite and so X is a discrete r.v. Possible outcomes Yes (Y) and No (N) YYY YYN YNY YNN NYY NYN NNY NNN Corresponding values of X 3 2 2 1 2 1 1 0 If we assume that each person is equally likely to answer YES or !O, then the eight outcomes above are all equally likely to occur. Notes 7 PROBABILITY DISTRIBUTIO& of a random variable The probability distribution of a random variable gives a listing of the possible values of the variable and the corresponding probabilities for those values....
View Full Document

This note was uploaded on 04/02/2012 for the course STA 2023 taught by Professor Bateh during the Spring '08 term at Florida State College.

Page1 / 6

Notes 7 - Notes 7 Random Variables A random variable (r.v.)...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online