## Basics of Statistics

Statistics is the analysis of data or information. In order for you to solve statistics, you have to know the basic information or data.

#### What is data?

Data is a group of different facts. It is divided into two types i.e. the qualitative and the quantitative fact.

Qualitative fact is a fact that describes. This type of fact is subjective and broad. For example, “it was funny”.

On the other hand, quantitative fact, from the name itself, represents the quantity of the data. You will see numbers in this data. And since quantitative data shows values and numbers, we can use this to solve for problems that require quantity and figures.

Data can be presented in many ways. Some of these examples are as follows:

1. Bar graph
This shows data in using bars.
2. Pie chart
Imagine a pie being divided into parts and what you get is a pie chart. Each part of the pie represents the data you present.
3. Line graph
This presents data that shows relationship such as changes in time, performance in time, among others.
4. Pictograms
This presentation of data can be used for presenting data to children since it shows the picture of the data collected and their relationship with each other.

In statistics, there are terms that we always encounter. These are mean, median and mode.

#### Mean

Mean number is the average of all the data you have presented.

To solve for the mean value of the data presented, all you have to do is to add up all the numbers and then divide the product by how many numbers you have added.

#### Example:

Find the mean of the following data

1. 5, 8, -2, 6, 7, 10
= 5 + 8 + (-2) + 6 + 7 + 10
= 34/6
= 5.67
2. 12, -8, -2, 5, 8, 14
= 12 + (-8) + (-2) + 5 + 8 + 14
= 29/6
= 4.83
3. 21, 22, 21, -9, 16, 15
= 21 + 22 + 21 + (-9) + 16 + 15
= 86/6
= 14.3
4. 32, 20, 18, 11, 10, -2
= 32 + 20 + 18 + 11 + 10 + (-2)
= 89/6
= 14.83
5. 16, 12, -8, 12, 32, 30, 5
= 16 + 12 + (-8) + 12 + 32 + 30 + 5
= 99/7
= 14.14
6. 10, -12, 25, 15
= 10 + (-12) + 25 + 15
= 38/4
= 9.5
7. 6, 8, 12, 10, 5
= 6 + 8 + 12 + 10 + 5
= 41/5
= 8.2
8. 13, 12, 8, -25
= 13 + 12 + 8 + (-25)
= 8/4
= 2

#### Median

When we say median, we mean the middle.

To find the median of a presented data, all you have to do is arrange the given numbers in the data presented and then find the middle number. In the event that you have two median values, all you have to do is to add the two medians and find its mean.

#### Example:

Find the median of the following:

1. 1, 2, 5, 16, 25
= 1, 2, 5, 16, 25
= 5
2. 36, 102, 75, 18, 3, 5
= 3, 5, 18, 36, 75, 102
= 18 + 36
2
= 27
3. 5, 2, 1, 32, 75, 18
= 1, 2, 5, 18, 32, 75
= 5 + 18
2
= 11.5
4. 1, 3, 14, 15, 8, 9
= 3, 8, 9, 14, 15
= 9
5. 75, 76, 101, 32, 10
= 10, 32, 75, 76, 101
= 75

#### Mode

Mode or the modal value is the number which appears the most.

To find it, you just have to look at the data presented, tally it and then find the number which appears the most. In the event that you find two modes in the given data, that is called “bimodal”. It could also have more than to modes, and that is called “multimodal”.

#### Examples:

1. 13, 25, 6, 25, 25, 11, 8, 9
= 25
2. 26, 3, 3, 3, 3, 2, 2, 2, 2, 5, 7, 28
= 3 and 2
3. 1, 2, 5, 3, 8, 8, 8, 9, 10, 21
= 8
4. 5, 3,16, 17, 17, 17, 3, 58
= 17
5. 16, 9, 9, 9, 9, 12, 1, 8, 8,8, 8
=9 and 8