Deciles

Illustrate the deciles for ungrouped data.

Calculate the specified decile of a given set of
data.

Solve problems involving deciles for ungrouped data.

Practice accuracy and mental alertness in computing
decile value.

A group of students obtained the following scores in their Statistics quiz:

8, 2, 5, 4, 8, 5, 7, 1, 3, 6, 9

Procedures:

➢ Arrange the scores in ASCENDING ORDER
➢ Identify the lowest score and highest score
➢ Solve for the lower quartile (Q1)
➢ Solve for the upper quartile (Q3)

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This activity is composed of four rounds. In each round, the groups

need to answer the given question within one-minute. When the time is
up, the group shows their answer written on the clean sheet provided.
Each round gives 5 points to those groups who answered the question
correctly.

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)

Identify the 4th decile in the given set of data:

28, 29, 35, 37, 42, 45, 47, 55

37

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)

Solve for the 7th decile of the given set of data:

23, 17, 14, 25, 30, 19, 24, 28

28

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)

Solve for the median of the given set of data:

22, 18, 13, 26, 29, 20, 23

22

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)

Solve for the sum of the D1 and D9 of the given set
of data:

42, 48, 53, 56, 59, 60, 63, 54, 44, 50

22

➢ How did you find the activity?
➢ How did you solve problems involving deciles for

ungrouped data?

➢ What is the formula you used to come up with the

answer?

The median divides the data set into two equal parts. Quartiles divide the data set into
four equal parts.
Deciles, on the other hand, are values that divide the data set into ten equal parts.
There are nine deciles which are denoted as D1, D2, D3,…, D10.

If the data are arranged in ascending order, D1 would mean that 10% of the
data lie below it. D2 would mean that 20% of the data lie below it.

Deciles are computed in the same way as the quartiles. First, we arrange the data
set in ascending order. Next, locate the position of the deciles in the data set. To do
this, we use the following formula:

And round off to the nearest integer. Finally, find the value that corresponds
to the calculated position

𝑃𝑜𝑠𝑖𝑡𝑖𝑜𝑛 𝑜𝑓 𝐷𝑖 =𝑖

10 𝑛 + 1

Mr. Redford is a bean farmer. One day, he counted the number of string beans that sprouted in his 15
plots.
These are the bean sprouts per plots.

17, 20, 35, 28, 28, 32, 25, 37, 46, 47, 55, 55, 52, 56, 60

For Group 1:

Find the value of D2, D6, and D8.

For Group 2:

Find the value of D3, D5, and D9.

For Group 3:

Find the value of D1, D4, and D7.

Direction: Complete the table below to evaluate the following decile for the given set of data.

Joan has an assignment to ask 11 of her classmates at random about their math grades. The data are given in the table below.

Students

Grades

1

89

2

76

3

75

4

88

5

75

6

72

7

84

8

80

9

75

10

81

11

85

Evaluate:

Find the position of

𝑃𝑜𝑠𝑖𝑡𝑖𝑜𝑛 𝑜𝑓 𝐷𝑖 = 𝑖

10 𝑛 + 1

Find 𝐷𝑖 =

1. 𝐷8
𝐷8 = _____

2. 𝐷5
𝐷5 = _____

𝟑. 𝐷9
𝐷9 = _____

𝟒. 𝐷2
𝐷2 = _____

5. 𝐷3
𝐷3 = _____

Direction: Make an online survey with your classmates. Think of a question that will
prompt you and your classmates to give a quantitative data. Solve for the values of
all deciles. Find your position based on the data values and make an interpretation.

Thank You For

Listening!