ELEC 303 – Random Signals Lecture 14 – Sample statistics, Limit Theorems Dr. Farinaz Koushanfar ECE Dept., Rice University Oct 21, 2010
Outline Sample statistics – Mean, variance, median, quantile Laws of large numbers Central limit theorem
Statistics
Sample mean and median
Sample median (cont’d)
Percentile
Why is percentile useful?
Variability measuring
Sample variance and standard deviation
Usages
Limit theorems
Law of large numbers
WLLN
Recall
WLLN
Sum of independent RV’s
Central Limit Theorem
Normal approximation to Binomial
Example: Polling
Example: Polling (Cont’d)
Limit Theorem
Strong Law of Large Numbers
Review of Law of Large Numbers
What does LLN Imply?