A single value that represents a data set, with the purpose of locating the center of the data set
The arithmetic mean, often called the mean, is the most frequently used measure of central tendency. It is the only measure in which all values play an equal role, and it is appropriate for interval or ratio data.
Properties of Mean
A set of data has only one mean
Mean for Ungrouped Data
1. Mean = Sum of all values / Number of Values
2. Sample Mean: x bar = (sum of x) / n
3. Population Mean: μ = (sum of x) / N
Sample Mean for Grouped Data
x bar = (sum of fx) / n
Population Mean for Grouped Data
μ = (sum of fx) / N
Median
The midpoint of the data array, the value that separates the upper half of the distribution from the lower half
The median is unique, there is only one median for a set of data?
properties of median
If n is odd, the median is the middle ranked
Median for Grouped Data
Median (Ranked Value) = LB + (N/2 - cf) / f * i
Mode
The value in the data set that appears most frequently. A data may not contain any mode if none of the values is "most typical".
Types of Mode?
Unimodal, Bimodal, Trimodal, Multimodal, No Mode
Unimodal - one value that occurs most frequently
Bimodal - two values with the greatest frequency
Trimodal - three values with the greatest frequency
Multimodal - more than three values with the greatest frequency
No Mode - all values have the same frequencies
Mean can be applied for interval or ratio data
properties of mean
All values in the data set are included in computing the mean
properties of mean
The mean is very useful in comparing two or more data sets
properties of mean
Mean is affected by the extreme small or large values on the data set
properties of mean
The mean cannot be computed for the data in a frequency distribution with an open-ended class
properties of mean
Mean is most appropriate in symmetrical data?
properties of mean
The median is found by arranging the set of data in ascending or descending form and getting the value of the middle observation?
Properties of Median
Median is not affected by the extreme small or large values?
Properties of Median
Median can be computed for ordinal, interval and ratio data?
Properties of median
Median is appropriate in a skewed data?
Properties of Median
If n is even, the median is the average of the two middle ranked values