Percentiles are a statistical measure that indicates the relative standing of a value within a dataset and are used to determine the percentage of data that falls below a certain threshold. For example, the 30th percentile represents the value below which 30% of the data points fall. The document provides a method to calculate percentiles using a formula and demonstrates finding the 30th percentile of a specific set of scores.

1. Percentile for
Ungrouped Data

2. PERCENTILE
A percentile is a certain percentage of a set of data.
Percentiles are used to observe how many of a given
set of data fall within a certain percentage range;
For example;
A thirtieth percentile indicates data that lies the 13%
mark of the entire data set.
2

3. 3
𝑄1
P25
Q2
P30
𝑄3
P75
𝑃0
D1
𝑃20
D2
𝑃30
D3
𝑃40
D4
𝑃50
D5
𝑃60
D6
𝑃70
D7
𝑃80
D8
𝑃90
D9

4. FORMULA
𝑃𝑚 =
𝑚
100
(N+1)
4
Where:
m represents the percentile
were finding
N represents the set of elements

5. EXAMPLE 1 5
Find the 30th percentile (P30) of the following scores 35, 42, 40, 28, 15,
23, 33, 20, 18, and 28.
Step 1: arrange the scores in increasing order
15 18 20 23 28 28 33 35 40 42
𝑃30 =
30
100
(N+1)
Step 2: solve for P30 which is actually the same with D3
=
30
100
(10+1)
=
33
10
= 3.3 𝑜𝑟 3
=
30
100
(11)
P30 is the 3rd element in the
scores15 18 20 23 28 28 33 35
40 42