MGEB11H3 Lecture Notes - Lecture 7: Random Variable, Poisson Distribution, Binomial Distribution
26 Oct 2018
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Mgeb11 lecture 7: (chapter 5) probability distribution: random variable, toss a coin 2 times. The 2 columns x , p(x) are called probability distribution of random variable x. Since p(s) = 1, so p(x = 0,1,2) = 1: expected value of a random variable, let x = # of children in a group of 100 families. Average value of x = (0*30) + (1*20) + (2*30) + (3*20) / 100. In general, let x be a random variable: the variance was. We now generalize it to variance of a random variable, let x be a random variable: 0. 1: let x be a random variable w/prob. distribution. P(x: e(x) = (0*0. 4) + (1*0. 3) + (2*0. 2) + (3*0. 1) = 1: var (x) = (0-1)^2(0. 4) + (1-1)^2(0. 3) + (2-1)^2(0. 2) + (3-1)^2(0. 1) P(x: you can also calculate variance using , laws of expectation, let x = a random variable, e(ax + b) = ae(x) + b.
