QMS 102 Lecture Notes - Lecture 4: Decision Rule, Weighted Arithmetic Mean, Central Tendency

• School: Ryerson University
• Department: Quantitative Methods
• Course: QMS 102
• Professor: Nursel Ruzgar

Document Summary

Usually we focus our attention two types of measures when describing population characteristics central location (eg. average) and variability or spread. The measure of central location re ects the location of all the actual data points. Arithmetic mean or average: is the most popular and useful measure of central location. Found by adding all the observations and dividing by the totally number of observations. Arithmetic mean for a sample is denoted with an x- bar : x . The sum of the values in the population divided by the population size (n) Where = population means n = population size xi = i- th value of the variable x. The most common measure of central tendency. Mean = sum of values divided by the number of values. Is a method of computing a kind of arithmetic mean of a set of numbers in which some elements of the set carry more important (weight) than others.