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Lecture Comments (3)

1 answer

Last reply by: Anil George
Thu Aug 16, 2012 11:00 AM

Post by Anil George on August 16, 2012

For the first Variance example, shouldn't the 3 and 5 be squared, since the sigma is squared in the variance equation? So the numbers should read 1 + 4(9) + 25 = 62?

Combining Independent Random Variables

  • If two random variables are independent, their joint probability is the product of the two marginal probabilities.

  • The mean of the sum of independent random variables is the sum of the means of the independent random variables.

  • The variance of the sum of independent random variables is the sum of the variances of the independent random variables.

Combining Independent Random Variables

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

  • Intro 0:00
  • Independence vs Dependence 0:09
  • Mean of Sums for Independent Random Variables 2:32
  • Example 4:02
  • Example 5:58
  • Variance for Sums of Independent Random Variables 8:49
  • Example 10:30
  • Example 12:26
  • Extra Example 1
  • Extra Example 2