All formulas of statistics

(1) Mean or Average:

Mean in theory is defined as the sum of all the elements of a set divided by the number of elements. We can get a fairly good idea about the whole set of data by calculating its mean. Thus the formula for mean is:

Mean = Sumofallthesetelements/Numberofelements 

The importance of mean lies in its ability to represent the whole dataset with a single value.

(2) Median:

Median is the middle value of a dataset. So, if a set consists of an odd number of values, then the middle value will be the median of the set. On the other hand, if the set consists of an even number of sets, then the median will be the average of the two middle values.

Thus, the median may be used to separate a set of data into two parts. To find the median of a set, we need to arrange the elements of the set in increasing order. Then find the middle value.

(3) Mode:

The mode in a dataset is the value that is most frequent in the dataset. The mode also summarizes the gdataset with single information.

(4) Variance:

We may want to measure the deviation of a set of data from their mean value. The variance of the particular dataset will always be positive. Variance is used in the calculation of Standard Deviation, which is a very important concept of statistics.

(5) Standard Deviation:

The standard deviation is defined as the square rooting of the variance of the data.