ECON 120A Lecture Notes - Lecture 16: Random Variable, Collectively Exhaustive Events, Variance
Document Summary
Mean and variance of a random variable. Binomial distribution continuous distribution-normal distribution functions of a rv. Example 1 rolling a die random variable (rv: variable that takes on numerical value associated with the random outcome of an experiment. X = # showing in the face: takes on 6 possible value, x is a possible value of rv x, x is discrete, x takes on a countable (finite or infinite) number of values. X=number of tails in 3 tosses e1 e2 e3 e4 e5 e6 e7. X = sum of the 2 faces. Pr(x<10) = 1 pr(x 10) = 1 p(10) p(11) p(12) = 1 6/36 = 30/36. X = x sum overall possible values of x: mutually exclusive, collectively exhaustive. Chapter 2-descriptive statistics: looking at samples, computed sample statistics. Possible values of x=0,1,2 x1=0 f1 ,x2=1 f2 ,x3=2 f3 n families. X = # of girls in families of 2 children.
