Statistical Sciences 2141A/B Lecture Notes - Lecture 11: Random Variable, Weighted Arithmetic Mean, Probability Distribution

• School: Western University
• Department: Statistical Sciences
• Course: Statistical Sciences 2141A/B
• Professor: Joe Raaymakers

Document Summary

The mean (or expected value) of a discrete rv x with pmf p(x) is. The mean can be thought of like a weighted average of the possible values of the rv x. Let the rv x be the number of power plants (out of a group of three) generating electricity and the pmf be as follows: E(x) = (0*0. 07) + (1*0. 23) + (2*0. 57) + (3*0. 13) = 1. 76. Sometimes the discrete random variable might be modelled in a function h(x). For example, the mean of a linear function ax + b of a discrete rv x with pdf f(x) can be given by. A computer store has purchased three computers of a certain type at apiece. The manufacturer has agreed to repurchase any computers still unsold after a specified period at apiece. Let x denote the number of computers sold and h(x) = revenue cost represent the profit.