## Exploring Variance and Arithmetic Mean in Statistics

What is **Statistics?**

Statistics is a branch of Mathematics dealing with the collection, organisation ,representation and interpretation of data.

This course deals with the graphical representation of data, measures of Central tendency: **Mean ,Median**Ā and Mode and Measures of Dispersion : Mean Deviation and **Standard Deviation. Learn about Variance and Arithmetic Mean in Statistics.**

Statistical data can be easily understood if we represent it in the form of **Charts**Ā and **graphs**. Here, you will study the following types of graphs: Pie Charts, Bar graphs, Histograms, Frequency Polygons. You will learn how to draw these graphs and interpret them. These form an integral part of quantitative aptitude tests.

You will learn how to draw a **Pie Chart.Ā **Ā

Given a pie chart you will answer questions based on it.

How to draw a bar graph to represent data is shown . You are taught how to interpret the data.

You will also learnĀ how to draw a **Histogram and Frequency Polygon**Ā and use these in analysing data.

Statistical data has the tendency to cluster around a central value. This is called Central tendency. The different ways of measuring Central tendency are Mean, **Median **and Mode. You will learn how to calculate these for grouped and ungrouped data, Problems of the type given below are discussed:

Learn the three types of methods for calculating arithmetic mean, namely, **direct method, shortcut method and step deviation **method.

Find the mean for a frequency distribution having class intervals using the Shortcut Method.

You are introduced to **Quartiles **and how to calculate them using the formula. A few of the problems include:

How to calculate the **mode**Ā for a given data.

In order to interpret the data, you should know how data is spread around a central value. This leads to measures of dispersion, namely **mean deviation and standard deviation.**

You will learn about Mean Deviation about the mean and mean deviation about the median for discrete and continuous frequency distributions. You move on to learning **variance and standard deviation**. Three methods of calculating the standard deviation are discussed. These include the Direct method, Shortcut method and Step Deviation method.

Learn the basics of **Regression Analysis**. You'll learn about dependent and independent variables, scatter diagrams and basic formulas of regression.

You'll be introduced to **Correlation Analysis**Ā and how to calculate it.

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