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.
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,
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