First we see the basic definition of statistics :-
Statistics is the subject which deals with the data. It is used to analyze, review, gather and to make conclusions from the data. It is used in Biology, physics, chemistry, mathematics, botony, phycology, industry, trade, ecomers, banking, business what not every thing need statistics for improvement.
Now first we will see the basic concepts of statistics.
Descriptive statistics :-
When we want to summarize the data based on the center of the data we use descriptive statistics.
The most popular ways to determine the centre is :
1.mean
2.median
3.mode
But in when we dive deep into this basic concept this descriptive statistics have a structure
Structure:-
Measures of central tendency :-
The name it self indicating that it measures the central value. This mainly consists of mean, median, mode.
Mean definition :-
Mean or average which is the center for data. Mathematically speaking mean is equal to the sum of all the values divided by the number of values.
Formula :-
Mean = (x1+x2+x3+ - - - - +xn) /n
Example :-
Suppose we have a data as 49,33,41,28,20 and we want to calculate mean for the given data. = ( 49 + 33 + 41 + 28 + 20 ) / 5
= 170 /5
= 34
34 is the mean of the given data.
Median definition :-
Median is the exact centre in the sorted (ascending or descending) data. Let use see this by an example. Consider the data which represents the markes of the students in a particular subject :- 3,13,7,5,21,23,39,23,40,23,14,12, 56,23, 29
The first step is arrange the data in ascending order :-
3,5,7,12,13,14,21,23,23,23,23, 29,39, 40,56.
Now we must find the center element. The total number of elements is 15 so the eighth element will be our central element :-
3,5,7,12,13,14,21,23,23,23,23,29, 39, 40, 56.
So we can say that the median in this case is 23.
If in case we have total elements as 14 (even number) them we cannot have just one center instead we have a pair of middle numbers for example consider the data which was ordered ascendingly
3,5,7,12,13,14,21,23,23,23,23,29, 40, 56
In this we have two middle numbers 21 and 23. To find the median value, add them and divide the sum by 2, that is 21+23 =44
then 44÷2 = 22
So, the median in this example is 22.
Mode definition :-
Mode is the most frequently occuring value in our data set. Normally the mode is used for categorical data where we wish to know the more common categorys. We can know about the mode more detailed with an example :-
Consider the data
3,5,7,12,13,14,21,23,23,23,23
Here the most frequently occuring value is 23, so we can say 23 is our mode.
Next blog we will see more about these descriptive statistics. My further blogs mainly deals with the python codes for this statistical concepts.
Statistics is a growing subject in India. Tomorrows world is waiting for statisticians because we have huge amount of data. Only statisticians can make use of this data.
Thank you for reading if you any doubts regarding this blog please ask me in the comment section.
