In this section, you will find many

Note that you can also contribute to this section by writing any kind of articles including (science, politics, health, education, etc, ...). Your knowledge and expertise can help others!!

Be helpfull to the others here]]>

Colors can be specified using hexadecimal color code, such as “#FFC00”

(Source: http://www.visibone.com)]]>

**Independent samples t test** is used to compare the means of two unrelated groups of samples. The aim of this article is to show you an **example**.

The **independent t-test formula** is :

\[ t = \frac{m_1 - m_2}{\sqrt{ \frac{S^2}{n_1} + \frac{S^2}{n_2} }} \]

- \(m_1\) and \(m_2\) are the means of the two groups being compared.
- \(n_1\) and \(n_2\) are the sizes of the two groups, respectively.
- \(S^2\) is the common
**variance**of the two samples.

The degrees of freedom are :

\[ df = n_1 + n_2 -2 \]

Once the **t test value** has been calculated, you have to use **t test table** to determine the **level of significance**.

As an example, we have a population of 20 people selected randomly (10 women and 10 men). We want to know whether women’s average weight is **significantly** different from men’s average weight.

In this typical **example** the two samples being compared are completely unrelated and you have to use **independent samples t test**.

The best free **statistics calculator software** can be used to calculate t-test statistics online.

If you want to do it with R, follow this link : **independent t test.

R is a free software environment for statistical analysis and graphics. It runs on different platforms : UNIX platforms, Windows and MacOS.

TANAGRA is a

Graphpad is an amazing statistical software which can guides your for statiscal tests and graphics analysis.

IBM SPSS software

XLSTAT is the leading data analysis and statistical solution for Microsoft Excel.]]>