Statistics is a branch in mathematics which deals with calculating the data and measuring to what extent a information is reliable It involves the below steps:
1) The collection of certain data

2) Classifying those based on numerical facts

3) Analyzing them

4) Finally interpreting the result.
There are many topics in statistics like arithmetic mean, geometric mean, standard deviation, summation, frequency distribution, mean deviation etc. To Calculate all these we can link to this page which computes all the statistical calculations.  
Statistical calculator is a online tool which gives you all statistical calculators. This calculator page links to all the statistical calculators and hence can do all statistical calculations instead of wasting your time in search each statistical calculator. You just have to click on the link based on which ever statistical calculator you want. 
Below are given all the statistical calculators you can get which ever calculator you desire by just clicking on it.
Following steps are used to find out the basic measurements in statistics.

Step 1: Note down the given observations.

Step 2: Calculate the mean using the following equation.

           $\bar{x}$ = 

Step 3: Median is the middle value, when the observation is arranged some numeric order.

Step 4: Mode is the repeated number in given observation.

Step 5:
Determine the standard deviation and variance using the equation.
           Standard deviation, $\sigma$ = $\sqrt{\frac{1}{n}\sum_{i=0}^{n}(x_{i}-\bar{x})^{2}}$
           Variance = $\sigma ^{2}$