Statistics

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numbers which are collected in order to provide information about something

also defined as the science of collecting and studying numbers.

Types of Statistics

1) Descriptive Statistics

2) Inferential Statistics

Descriptive Statistics: In descriptive statistics, the data is described in a summarized way. The summarization is done from the sample of the population using different parameters such as Mean or Standard Deviation. Descriptive statistics are a way of using charts, graphs & summary measures to organize, represent and explain a set of data.

Data is typically arranged and displayed in tables or graphs summarizing details such as histograms, pie charts, bars, scatter plots, etc.

Descriptive statistics are just descriptive and thus do not require generalization beyond the data collected.

2) Inferential Statistics: In inferential statistics, we try to interpret the meaning of descriptive statistics. After the data has been collected, analyzed, and summarized we use inferential statistics to describe the meaning of the collected data.

inferential statistics uses the probability principle to assess whether the trends contained in the research sample can be generalized to the larger population from which the sample originally comes.

inferential statistics are intended to test hypotheses and investigate the relationship between variables and can be used to make population predictions.

Inferential Statistics are used to draw conclusions and inferences, i.e to make a valid generalization from samples

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Population: It is actually a collection of a set of individual or objects or events whose properties are to be analyzed

Sample: It is the subset of the population

The measure of Central Tendency: Measure of central tendency is also known as summary statistics that is used to represent the center point of a particular value of data set or a sample set

In statistics, there are 3 common measure of central tendency as shown in the figure

1) Mean (Average)

Formula: sum of all the terms / total no of terms

Cars Milage Cylinder

Swift 21.3 3

BMW 20.8 4

Audi 18 5

2) Median

Cars Milage Cylinder

Swift 21.3 3

BMW 20.8 4

Audi 18 5

Ertiga 15 4

15 18 20.8 21.3 (in case of even numbers)

-> 18+20.8

= 38.8 / 2 => 19.4 (Median Value)

in the case of odd numbers

18 20.8 21.3 (Median Value would be 20.8)

3) Mode (finds out which is the most repetitive record in the data set)

The mode value in the given data set is 2 (it is repeated the maximum number of time in the data set)

age

10

2

3

4

2

6

4

2

7

7

10

4

2