STAT 3460 Lecture Notes - Lecture 3: Cumulative Distribution Function, Random Variable, Standard Deviation

• School: Ohio State University
• Department: Statistics
• Course: STAT 3460
• Professor: Chenggong Han, Laura Kubatko, Min Ho Cho, Yuan Gao

Document Summary

Chapter 3: cumulaive distribuion funcion of a discrete random variable the funcion that speciies the probability that a random variable is less than or equal to a given value. P(x x) the probability that x is less than or equal to a certain number x. F(2) = p(0) + p(1) + p(2) = 7/8. F(3) = p(0) + p(1) + p(2) + p(3) = 1: mean and variance for discrete random variables. Populaion mean the mean of a hypotheical sample that follows the probability distribuion perfectly. X = xp(x: example: toss a coin. X = 0(1/8) + 1(3/8) + 2(3/8) + 3(1/8) X = 3/2: the mean can also be called the expected value . Populaion variance the variance of a hypotheical sample that follows the probability distribuion perfectly. Populaion standard deviaion the square root of populaion variance. 2 = [(0)2(1/8) + (1)2(3/8) + (2)2(3/8) + (3)2(1/8)] (3/2)2.