QMS 102 Lecture Notes - Lecture 4: Decision Rule, Categorical Variable, Level Of Measurement

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

Document Summary

Measures of central location - mean, median, mode. Measures of central location reflects the locations of all actual data points. Mean (aka average): add up all the values and divide by the amount of values there are. Not meaningful for nominal or ordinal data. Weighted average is similar to evaluating final marks for a course. If it is an off set of numbers it is that value. If it is an even set of numbers, it is the mean of the two middle numbers. Median position (in numerical order, smallest to largest) n + 1. Can be calculated for ordinal data, but can"t be interpreted as the centre of location. Used for either numerical or categorical data. There may be no mode/there may be multiple modes. In a small sample, it may not be a good measure of central location. Mean is generally used, unless extremes (outliers) exist. Describe the central location of a single set of interval data.