# Statistics :

The science of collecting, describing and interpreting data. ## Important note on Statistics:

Many studies generate large number of data points and to make sense of all that data researchers use statistics that summarize the data providing a better understanding of overall tendencies within the distributions of scores.

It is a branch of mathematics dealing with the collection, analysis, explanation presentation and organization of data.

Statistics deals with all aspects of data including the planning of data collections in terms of the design of surveys experiments.

Two main statistical methods are used in data analysis descriptive statistics which summarize data from a sample using indexes such as the mean or standard deviation

We use statistics for many reasons:

To mathematically describe

To draw conclusions from our results

To test hypotheses

To test for relationships among variables

Helps us recognize underlying trends and tendencies in the data.

### Two types of statistics :

Numerical representation of data basically divided into two types

Descriptive Statistics: Collection, Presentation and summarize data

Inferential Statistics : Making decisions and drawing conclusions about populations

### Descriptive Statistics :

It is a summary statistics that quantitatively describes a collection of information and analyzing the data. Summarize a sample data, rather than use data learn about the population that the sample of data is thought to represent.

I)Measures of central tendency:

It means that the central position of the frequency distribution for the group for data.

II)Measures of dispersion:

It means that the process of distributing data at a certain speed.

III)Measures of symmetry:

It means that symmetric distribution of a group of data. Like positively skewed and negative skewed distribution.

### 2.Inferential:

Test for the significant difference between groups / significant relationships among variables within the sample.

I) t – ratio, chi-square, and beta – value within a group