STAT 255 Study Guide - Final Guide: Mutual Exclusivity, Probability Density Function, Central Limit Theorem

• School: University of Victoria
• Department: Statistics
• Course: STAT 255
• Professor: Eric Cormier

Document Summary

Mean: the average of the observations: population mean: , sample mean: = Median: the 50th percentile (number right in the middle) Mode: most frequent observation (not useful in this class) Events are mututally exclusive is pr(a&b) = 0. General addition rules: pr(ab) = pr(a) + pr(b) pr(ab, pr(ab) = pr(a) + pr(b) pr(ab) Relative risk: rr : a rr 1 implies no relationship between the risk factor and the disease. False-positive rate: = pr(test results are positive | subject is a true negative) False-negative rate: = pr( test results are negative | subject is true positive) Two events are independent if the outcome of one occurring does not affect the outcome of the other occurring: events are independent if and only if pr(a|b)=p(a) Pr(ab) = pr(a)pr(b) *only true for independent events. Pr(ab|c) = pr(a|c) + pr(b|c) pr(ab|c) Discrete random variables use the pdf and cdf: probability density function (pdf): lists each possible value the random variable can assume.