### Mean, Median and Mode are the most common terms used from the field of statistics in our day to day life. Let us revisit them from the practical aspect.

Do you know what a central tendency is? How many types of them do they exist and when to use which one? Mean, Median, Mode, Standard Deviation, Range, quartile etc. are few of the starting terminologies in statistics, which can be confusing at times. It’s not just the mean or the average which is only important, but there are others too. Let us see them one by one.

What do you meant by central tendency? The value, which lies at the center of the data set. That value which is equidistant from the remaining data in the data set. In the numbers 1 to 7, the central number is 4 i.e. there are three numbers to its left 1, 2 and 3, and there are three numbers to its right 5, 6 and 7.

DATA SET | CENTRAL NUMBER | DIFFERENCE |

1 | 4 | -3 |

2 | 4 | -2 |

3 | 4 | -1 |

4 | 4 | 0 |

5 | 4 | 1 |

6 | 4 | 2 |

7 | 4 | 3 |

Now when you sum the difference you get the value 0. Therefore, we can say that the central tendency of this data set of seven numbers is 4. If there is any need of a number to represent this data set, then 4 is that number, this number is the central property of this data set, similar to what 12 is to one dozen.

Just consider this data set 1 to 7 represent the number of units of different items sold in a store in a day –

ITEM | NO OF UNITS SOLD IN A DAY |

Pencil | 1 |

Pen | 2 |

Notebook | 3 |

Eraser | 4 |

White Paper | 5 |

Blades | 6 |

Graph Paper | 7 |

### MEAN

**Mean** – it is the average of the numbers. The mean of the above total quantity of 7 items sold is (1+2+3+4+5+6+7)/7 = 28/7 = 4 The store sold 4 items on an average on that day.

### MEDIAN

**Median** – The central value of the data set. As described in the beginning, 4 is the central value of the data set.

### MODE

**Mode** – The data, which occurs more in the data set, is called mode. In this data set there is no such number which occurs more than once. Suppose apart from eraser, no of white paper sold was also 4, and the remaining data stays same, then 4 would become the mode. However, this is not the case here.

We see that the mean and the median are same, 4. All the remaining data are equidistant from this number 4. Therefore, we can say that the central value, which represents this data set, is 4 i.e. the Central Tendency.