Measures of Central Tendency

The Measure of Central Tendency provides a very convenient way of describing a set of scores with a single number that describes the performance of the group.

There are three commonly used Measure of Central Tendency. These are the following :

• Mode
• Median
• Mean

Mode : The mode of a data set is the element that occurs the most often. it is uncommon for a data set to have more than one mode.

Median : The Median of a data set is dependent on whether the number of the elements in the data set is odd and even. 

First reorder the data set from the smallest to the largest. Mark off high and low values until you reach the middle. 

Mean : The mean takes the total of all the values and spreads the total out evenly to get a average. 

It is by adding all of the numbers in the data together and dividing by the number elements in the data set.

Formula of mean :
Mean = Total number / Number of values

**Range :  The range of a set of data is the difference between the largest and smallest value.

Formula of range
Range = largest value - smallest value

Example 1 :
The average age of Diploma Information and Technology in group 1 are :

23, 25,18,20,21,23,16,18

Mean :

Mean = Total number / Number of values

16+18+18+20+21+23+23+25 = 164                                    Number of values = 8

162/8 = 20.5

Median :

16,18,18,20,21,23,23,25

*** There are 2 numbers in the middle. The median is in the middle of these and it can be only one median.

  
Median = 20.5

Mode :
16,18,18,20,21,23,23,25

Mode = 18,23

Range :
Range = largest value - smallest value

25-16= 9

Example 2 :

Sarah went played bowling. This is her score :

6,10,9,2,8

Mean :
Mean = Total number / Number of values

2+6+8+9+10 = 35                                                                Number of values = 5

35/5 = 7

Median :

2,6,8,9,10 = 8

Mode :

= None [no repeating number]

Range : 

Range = largest value - smallest value

10-2 = 8