Organisation Of Data In Statistics Class 11 Notes PDF Free Download
The process of grouping data according to their characteristics is known as classification of data.
2. Objectives of Classification :
a] To simplify complex data
b] To facilitate understanding
c] To facilitate comparison
d] To make analysis and interpretation easy.
e] To arrange and put the data according to their common characteristics.
3. Statistical Series :
Systematic arrangement of statistical data
I. Can be on the basis of individual units : The data can be individually presented in two forms:
i] Raw data : Data collected in original form.
ii] Individual Series : The arrangement of raw data individually. It can be expressed in two ways.
a] Alphabetical arrangement : Alphabetical order
b] Array : Ascending or descending order.
II. Can be on the basis of Frequency Distribution : Frequency distribution refers to a table in which observed values of a variable are classified according to their numerical magnitude.
1. Discrete Series :
A variable is called discrete if the variable can take only some particular values.
2. Continuous Series :
A variable is called continuous if it can take any value in a given range. In constructing continuous series we come across terms like:
a] Class : Each given internal is called a class e.g., 05, 510.
b] Class limit : There are two limits upper limit and lower limit.
c] Class interval : Difference between upper limit and lower limit.
d] Range : Difference between upper limit and lower limit.
e] Midpoint or Mid Value :
f] Frequency : Number of items [observations] falling within a particular class.
i] Exclusive Series : Excluding the upper limit of these classes, all the items of the class are included in the class itself. E.g., :
ii] Inclusive
Marks 
010  1020 
2030 
3040 
Number of Students  2  5  2  1 
Series : Upper class limits of classes are included in the respective classes. E.g.,
Marks 
09 
1019 
2029 
Name of Students 
2  5  2 
The lower limit of the first class and upper limit of the last class are not given. E.g.,
Marks  Below 20  2030  3040  4050  50 and above 
Number of Students  7  6  12  5  3 
iii] Cumulative Frequency Series : It is obtained by successively adding the frequencies of the values of the classes according to a certain law.
a] ‘Less than’ Cumulative Frequency Distribution : The frequencies of each classinternal are added successively.
b] ‘More than’ Cumulative Frequency Distribution : The more than cumulative frequency is obtained by finding the cumulative totals of frequencies starting from the highest value of the variable to the lowest value.



Please send your queries to ncerthelp@gmail.com you can aslo visit our facebook page to get quick help. Link of our facebook page is given in sidebar
Copyright @ ncerthelp.com A free educational website for CBSE, ICSE and UP board.