Saturday, January 30, 2010

Statistics, Frequency and Frequency Distributions

Statistics: - By “statistics” we mean aggregate or combination of facts affected to a marked extends by multiplicity of causes, numerically expressed and estimated according to reasonable standards of accuracy, collected in a systematic manner and placed in relation to each other.
There are two ways of statistics:
1. Frequency Distribution and
2. Graphical Distribution.
Frequency: - The way to count the number of items a particular value is repeated, is called the frequency of any class.
That means, frequency is the total number of items that a particular value is repeated in a table or data.
Frequency Distributions: - A set of classes together with the frequencies of occurrence of values in again set of data, presented in a tabular form, is referred to as a frequency distribution.
frequency distribution


Construct a frequency distribution from the class marks of EEE 36 Batch who got the numbers in total trimester in statistics and probability.
Course:
97, 13, 81, 25, 37, 55, 19, 33, 59, 46, 67, 43, 12, 87, 90, 65, 76, 81, 79, 13, 5, 12, 35, 17, 46, 65, 43, 12, 85, 93,
Solution:
Here, the lowest value=5
And the highest value=97
For this kind of ungrouped data we have to choose k in such a way that 2k ≥ number of variables.
Here, k=5
So 2k = 25 = 32 > 30