Stat 321 – Day 15Last Time – Continuous RV BasicsSpecial property of exponentialGamma DistributionWeibull distributionNormal distributionSlide 7Slide 8LognormalFor ThursdayStat 321 – Day 15More famous continuous random variables“All models are wrong; some are useful” -- G.E.P. BoxLast Time – Continuous RV BasicsProbability density function (pdf), f(x)Allows us to determine the probability of an interval of values through integrationf(x) by itself doesn’t tell us muchP(X=x) = 0 and P(X < x) = P(X < x)E(X) = xf(x) dxF(x) = x f(t) dtSpecial property of exponentialP(X > 5 | X > 2)If you have already waited 2 minutes for the bus, what is the probability you will have to wait at least 5 minutes?= P(X > 5)/P(X > 2) = e-5/ e-2 = e-3 = P(X > 3)The probability of having to wait at least 3 additional minutes is the same as the probability of having to wait at least 3 minutes.“Memoryless property”Gamma DistributionWeibull distributionNormal distributionLognormalFor ThursdayQuiz on HW 4Lab 5 due MondayHW 5 posted
View Full Document
Unlocking...