Statistics 1

Statistics 1

1. Discrete Random Variables

   • Discrete Random Variables quick quiz
   • Probability Distributions
     • E(X) = μ
       • Σxp multiply each value of x by its corresponding probability, then sum
     • Var(X)
       • Σx^2 * p - μ^2 Square each value of x, multiply by corresponding probablity, sum and subtract μ^2
   • Geometric Distribution
     • X~Geo(p)
     • Keep going until a success
     • P(X=x)
       • P(X=x) = (1-p)^(x-1) * p x=1,2,3...
     • E(X)
       • E(X) = 1/p
     • P(X>x)
       • P(X>x) is the same as (1-p)^x 
   • Binomial Distribution
     • X~B(n,p)
       • n number of events, p probability of success
     • P(X=x)
       • P(X=x)= nCx * p^x * (1-p)^(n-x) x+0,1,2... n
     • E(X)
       • E(X) = np
     • Var(X)
       • Var(X) = np(1-p)