Page 29 - Quantitative Data Analysis

Quantitative Data Analysis
Simply Explained Using SPSS

Measures of Central Tendency

A measure of central tendency is a descriptive statistic that
describes a set of data; central value of a data set.
1. Mean

The mean is the arithmetic average of all observations
within a set of data for a specific variable.

1. Used for interval and ratio data
2. Units are the same as the original scale.

Notation:

̅
1. Sample mean: , “x-bar”
2. Population mean: , greek letter “mu”

Formula:

∑
̅

For example: The test scores of five students are: 33, 38, 42, 45, 48.
The mean of five students test scores is

̅

This mean value of 41.20 is the representation of entire set of data.

The Theory and Applications of Statistical Inferences 13