Basic data exploring and handling

Content:
Sorting
Ordering
Ranking
Classification
Ratio
Percentage
Rate
standardised rate


Sorting
Sorting is any process of arranging items systematically. Sorting a data is a way of organising data and we can identify different patterns that will not be possible to identify in an unorganised data.

Example:
Raw data (Gender of students)
Male, Female, Male, Female, Female, Female, Male, Female, Male, Male, Female.

Sorted data
Male, Male, Male, Male, Male, Female, Female, Female, Female, Female, Female.

The sorted data make a pattern where you can find that there is more female than male.




Ordering
Ordering is another way of organising data and identify possible patterns.

Example:
Raw data (Marks of students)
65, 50, 54, 41, 59, 71, 54, 91, 63, 71.

Ascending order data:
41, 50, 54, 54, 59, 63, 65, 71, 71, 91.
Descending order data:
91, 71, 71, 65, 63, 59, 54, 54, 50, 41.

Ranking
A ranking is a relationship between a set of items such that, for any two items, the first is either 'ranked higher than', 'ranked lower than' or 'ranked equal to' the second.

Ranking when there is same figures.

Classification
Classification is grouping of numbers and enable summarisation of data, Data can be classified according to different level of data.
Note that a summarised data cannot be expanded whereas an expanded data can be summarised. For e.g., we cannot change the Rs 5,000 intervals into Rs 2,500 from the table below.

Ratio
A relationship between two quantities, normally expressed as the quotient of one divided by the other. For example, if a box contains six red marbles and four blue marbles, the ratio of red marbles to blue marbles is 6 to 4, also written 6:4.
6:4 is not equal as 4:6.
A ratio can also be expressed as a decimal or percentage.

Percentage
In mathematics, a percentage is a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign, "%",
Percentage change = ((new-old)/old)*100

Rate
A value describing one quantity in terms of another quantity. A common type of rate is a quantity expressed in terms of time, such as percent change per year.
Use in economics e.g: inflation rate,unemployment rate, growth rate, interest rate, etc..
We must be careful when comparing rates with different population.

Standardised rate