Massachusetts Institute of Technology

Department of Physics

Physics 8.04 Wed Oct 11 13:59:46 EDT 1995

Quantum Physics I, Spring 1995

Supplemental Notes on Statistical Averages

• Introduction
• Random Variables
• Averages and Joint Distributions
  • Definition of Average
  • Joint Probability Distribution
  • Basic Properties of the Average
• Variance and Standard Deviation
  • Definition of Variance
  • Basic Properties of the Variance
  • Examples of Variance
• Independence and the Variance of a Sum of Independent Variables
  • Independence of Random Variables
  • Average of the Product of Two Independent Random Variables
  • Variance of the Sum of Two Independent Random Variables
  • The Variance of the Sum of Correlated Variables May Be Zero!
• Applications
  • Minimal Spreading of a Wave Packet
  • Poisson(Counting) Statistics
• About this document ...

Postscript Version