1. 8.5 Probability Distributions; Expected Value This presentation is copyright by Paul Hendrick © 2005, Paul Hendrick All rights reserved

2. 8.5 Probability Distributions; Expected Value Weighted Average - Preliminaries (1) Suppose you drive the 180 miles to Dallas at 60 mph and you drive the return trip at 90 mph, what was your average speed for the trip? A) 75 mph B) 80 mph C) 70 mph D) 72 mph E) 79 mph

3. 8.5 Probability Distributions; Expected Value Weighted Average - Preliminaries (2)Suppose you are taking a chemistry class, and you make a grade of 60 % on Exam 1 which counts 30% of the course grade and you make a grade of 90 % on a lab practical which counts 20 % of the course grade, then what is your current average in the class? A) 75 % B) 80 % C) 70 % D) 72 % E) 74 %

4. 8.5 Probability Distributions; Expected Value Weighted Average - Preliminaries D) was the correct answer for each! You must do weighted averages for each!

5. 8.5 Probability Distributions; Expected Value Weighted Average Let X & Y be two lists of numbers, with n elements in each list. The weighted average of X with respect to Y is denoted by X Y and calculated by

6. 8.5 Probability Distributions; Expected Value