Random variables

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Use has been made of the material at
www.columbia.edu/cu/psychology/ courses/S1610q/06RandomVariables.ppt
www.math.usu.edu/~vukasino/ teaching/fall2001/Lecture_notes/unit3.PDF
Statistics for Management by Levin and Rubin

What are random variables?
A random variable is a variable that takes on different values as a result of the outcomes of a random experiment.
A random experiment is a process for which more than one outcome is possible. The outcome of a random experiment can be numerical value itself (e.g., tossing a die where we get the values of 1,2,3,4,5,6), but it does not have to be numerical value (e.g., tossing a coin where we get a head or a tail, drawing a ball from a bag, having a baby-boy or a baby-girl). However, we can always assign numerical value to an outcome of a random experiment. ?By assigning numerical value to the outcome of a random experiment, we get a RANDOM VARIABLE, which we (usually) denote by x.

Let x represent a quantitative variable that is measured or observed in an experiment. We say that x is a random variable because the value that x takes on in a given experiment is a chance or random outcome.

Suppose we choose a student at random from the class (random experiment) and ask him/her for age, weight, and number of siblings. Age, weight, and number of siblings describe properties of a ...