PERCENTAGE AND PERCENTILE-Gr VI

PERCENT

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Percentage(℅. pct or pc) is a number or ratio expressed as a fraction of 100.

Percentage changes and comparisons can takes valuse greater than 100 or less than 0 (negative values)

Per mille("‰") is a number or ratio expressed as a fraction of 1000.


Percentage or per mille has no dimensions (it is a pure number).

Example 1:-
30% is equal to 30/100 or 0.30.

If 30%of students in class are females. It means 30 out of 100. If no. of students is 300. Then 30% of 300 is 30/100 x 300 whiich equals 90.
Means 90 out of 300 students are females.

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Example 2
An increase in price of a pack of biscuits from 5$ to 6$ is equal to how many percent?
It means 1$ increase
1/5 x 100 equals 20%.

PERCENTILE
A percentile (or a centile) is value below which a given percentage of observations in a group of observations fall.

It is used when the sample size ia very large and the probability diatribution is continous.

Example 1
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In an online examination, student A got 60th percentile marks.It means that 60% of students have marks less than students A. Marks obtained by student A may or may not be 60%.

Example 2

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Four students A , B, C, and D appeared for a test.Out of 10 marks student A got 8 marks, student B got 6 marks and student c got 4 marks and student D got 3 marks.

It means that student A got 100 percentile marks.
Student B got 75 percentiles.
Student C got 50 percentilee.
Student D got 25 percentiles.

Now let us calculate their percentage which is as below A-80%
B-60%
C-40%
D-30%.