Long Questions
Marks obtained | 60-75 | 65-70 | 70-75 | 75-80 | 80-85 | 85-90 |
---|---|---|---|---|---|---|
No. of students | 7 | 5 | 8 | 4 | 3 | 3 |
Tabulating given data for calculation of Quartile deviation (QD),
Marks obtained | Number of students (f) | Cumulative frequency (c.f.) |
---|---|---|
60-75 | 7 | 7 |
65-70 | 5 | 12 |
70-75 | 8 | 20 |
75-80 | 4 | 24 |
80-85 | 3 | 27 |
85-90 | 3 | 30 |
N = 30 |
Position of first quartile = item = item = 7.5th item
In c.f. column, 12 is just greater than 7.5 so its corresponding class is 65-70.
∴ L = 65, f = 5, c.f. = 7, i = 5
Now, we know,
Q1 = L + × i
or, Q1 = 65 + × 5
∴ Q1 = 65.5
Position of third quartile = item = item = 22.5th item
In c.f. column, 24 is just greater than 22.5 so its corresponding class is 75-80.
∴ L = 75, f = 4, c.f. = 20, i = 5
Now, we know,
Q3 = L + × i
or, Q3 = 75 + × 5
∴ Q3 = 78.125
Finally,
QD = = = 6.3132
Weight (kg) | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 | 70-80 |
---|---|---|---|---|---|---|
No. of person | 5 | 15 | 10 | 8 | 6 | 2 |
Tabulating given data for calculation of Quartile deviation (QD),
Weight | Number of person (f) | Cumulative frequency (c.f.) |
---|---|---|
20-30 | 5 | 5 |
30-40 | 15 | 20 |
40-50 | 10 | 30 |
50-60 | 8 | 38 |
60-70 | 6 | 44 |
70-80 | 2 | 46 |
N = 46 |
Position of first quartile = item = item = 11.5th item
In c.f. column, 20 is just greater than 11.5 so its corresponding class is 30-40.
∴ L = 30, f = 15, c.f. = 5, i = 10
Now, we know,
Q1 = L + × i
or, Q1 = 30 + × 10
∴ Q1 = 34.33
Position of third quartile = item = item = 26.25th item
In c.f. column, 38 is just greater than 34.5 so its corresponding class is 50-60.
∴ L = 50, f = 8, c.f. = 30, i = 10
Now, we know,
Q3 = L + × i
or, Q3 = 50 + × 10
∴ Q3 = 55.63
Finally,
QD = = = 10.65 kg
Class interval | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 |
---|---|---|---|---|---|
Frequency | 8 | 16 | 4 | 4 | 3 |
Tabulating given data for calculation of Quartile deviation (QD),
Class interval | Frequency (f) | Cumulative frequency (c.f.) |
---|---|---|
20-30 | 8 | 8 |
30-40 | 16 | 24 |
40-50 | 4 | 28 |
50-60 | 4 | 32 |
60-70 | 3 | 35 |
N = 35 |
Position of first quartile = item = item = 8.75th item
In c.f. column, 24 is just greater than 8.75 so its corresponding class is 30-40.
∴ L = 30, f = 16, c.f. = 8, i = 10
Now, we know,
Q1 = L + × i
or, Q1 = 30 + × 10
∴ Q1 = 30.47
Position of third quartile = item = item = 26.25th item
In c.f. column, 28 is just greater than 26.25 so its corresponding class is 40-50.
∴ L = 40, f = 4, c.f. = 24, i = 10
Now, we know,
Q3 = L + × i
or, Q3 = 40 + × 10
∴ Q3 = 45.63
Finally,
QD = = = 7.58
Size | 4-8 | 8-12 | 12-16 | 16-20 | 20-24 | 24-28 | 28-32 | 32-36 | 36-40 |
---|---|---|---|---|---|---|---|---|---|
Frequency | 6 | 10 | 18 | 30 | 15 | 12 | 10 | 6 | 5 |
Tabulating given data for calculation of Quartile deviation (QD),
Size | Frequency (f) | Cumulative frequency (c.f.) |
---|---|---|
4-8 | 6 | 6 |
8-12 | 10 | 16 |
12-16 | 18 | 34 |
16-20 | 30 | 64 |
20-24 | 15 | 79 |
24-28 | 12 | 91 |
28-32 | 10 | 101 |
32-36 | 6 | 107 |
36-40 | 5 | 112 |
N = 112 |
Position of first quartile = item = item = 28th item
In c.f. column, 34 is just greater than 28 so its corresponding class is 12-16.
∴ L = 12, f = 18, c.f. = 16, i = 4
Now, we know,
Q1 = L + × i
or, Q1 = 12 + × 4
∴ Q1 = 14.67
Position of third quartile = item = item = 84th item
In c.f. column, 91 is just greater than 84 so its corresponding class is 24-28.
∴ L = 24, f = 12, c.f. = 79, i = 4
Now, we know,
Q3 = L + × i
or, Q3 = 24 + × 4
∴ Q3 = 25.67
Finally,
QD = = = 5.5
Height (in inches) | 60-62 | 62-64 | 64-66 | 66-68 | 68-70 | 70-72 |
---|---|---|---|---|---|---|
No. of students | 4 | 6 | 8 | 12 | 7 | 2 |
Tabulating given data for calculation of Quartile deviation (QD),
Height | Number of students (f) | Cumulative frequency (c.f.) |
---|---|---|
60-62 | 4 | 4 |
62-64 | 6 | 10 |
64-66 | 8 | 18 |
66-68 | 12 | 30 |
68-70 | 7 | 37 |
70-72 | 2 | 39 |
N = 39 |
Position of first quartile = item = item = 9.75th item
In c.f. column, 10 is just greater than 9.75 so its corresponding class is 62-64.
∴ L = 62, f = 6, c.f. = 4, i = 2
Now, we know,
Q1 = L + × i
or, Q1 = 62 + × 2
∴ Q1 = 63.92
Position of third quartile = item = item = 29.25th item
In c.f. column, 30 is just greater than 29.25 so its corresponding class is 66-68.
∴ L = 66, f = 12, c.f. = 18, i = 2
Now, we know,
Q3 = L + × i
or, Q3 = 66 + × 2
∴ Q3 = 67.875
Finally,
QD = = = 1.978 inches
Coefficient of quartile deviation = = = 0.03
Expenditure | 0 ≤ x ≤ 10 | 10 ≤ x ≤ 20 | 20 ≤ x ≤ 30 | 30 ≤ x ≤ 40 | 40 ≤ x ≤ 50 |
---|---|---|---|---|---|
No. of workers | 5 | 15 | 10 | 8 | 6 |
Tabulating given data for calculation of Quartile deviation (QD),
Expenditure | Number of workers (f) | Cumulative frequency (c.f.) |
---|---|---|
0-10 | 5 | 5 |
10-20 | 15 | 20 |
20-30 | 10 | 30 |
30-40 | 8 | 38 |
40-50 | 6 | 44 |
N = 44 |
Position of first quartile = item = item = 11th item
In c.f. column, 20 is just greater than 11 so its corresponding class is 10-20.
∴ L = 10, f = 15, c.f. = 5, i = 10
Now, we know,
Q1 = L + × i
or, Q1 = 10 + × 10
∴ Q1 = 14
Position of third quartile = item = item = 33th item
In c.f. column, 38 is just greater than 33 so its corresponding class is 30-40.
∴ L = 30, f = 8, c.f. = 30, i = 10
Now, we know,
Q3 = L + × i
or, Q3 = 30 + × 10
∴ Q3 = 33.75
Finally,
QD = = = 9.875
Coefficient of quartile deviation = = = 0.414
The following are the marks obtained by class 9 students in their internal examination. Taking class interval of (10-20) as first class, prepare a frequency distribution table and find the quartile deviation. Also find its coefficient from the following data:
22, 25, 46, 34, 57, 69, 44, 36, 12, 27, 50, 36, 35, 62, 46, 52, 54, 61, 66, 55, 29, 39, 40, 33, 14, 41, 25, 20, 16.
Given data,
22, 25, 46, 34, 57, 69, 44, 36, 12, 27, 50, 36, 35, 62, 46, 52, 54, 61, 66, 55, 29, 39, 40, 33, 14, 41, 25, 20, 16
Tabulating given data starting from class interval of (10 - 20) for calculation of Quartile deviation (QD),
Class interval | Frequency (f) | Cumulative frequency (c.f.) |
---|---|---|
10-20 | 3 | 3 |
20-30 | 6 | 9 |
30-40 | 6 | 15 |
40-50 | 5 | 20 |
50-60 | 5 | 25 |
60-70 | 4 | 29 |
N = 29 |
Position of first quartile = item = item = 7.25th item
In c.f. column, 9 is just greater than 7.25 so its corresponding class is 20-30.
∴ L = 20, f = 6, c.f. = 3, i = 10
Now, we know,
Q1 = L + × i
or, Q1 = 20 + × 10
∴ Q1 = 27.083
Position of third quartile = item = item = 21.75th item
In c.f. column, 25 is just greater than 21.75 so its corresponding class is 50-60.
∴ L = 50, f = 5, c.f. = 20, i = 10
Now, we know,
Q3 = L + × i
or, Q3 = 50 + × 10
∴ Q3 = 53.5
Finally,
QD = = = 13.21
Coefficient of quartile deviation = = = 0.33
The following are the marks obtained by class 9 students in their internal examination. Taking class interval of (10-20) as first class, prepare a frequency distribution table and find the quartile deviation. Also find its coefficient from the following data:
21, 45, 60, 57, 15, 41, 48, 50, 34, 29, 56, 40, 14, 62, 28, 70, 22, 30, 38, 74, 13, 47, 20, 53, 64, 34, 75, 66.
Given data,
21, 45, 60, 57, 15, 41, 48, 50, 34, 29, 56, 40, 14, 62, 28, 70, 22, 30, 38, 74, 13, 47, 20, 53, 64, 34, 75, 66
Tabulating given data starting from class interval of (10 - 20) for calculation of Quartile deviation (QD),
Class interval | Frequency (f) | Cumulative frequency (c.f.) |
---|---|---|
10-20 | 3 | 3 |
20-30 | 5 | 8 |
30-40 | 4 | 12 |
40-50 | 5 | 17 |
50-60 | 4 | 21 |
60-70 | 4 | 25 |
70-80 | 3 | 28 |
N = 28 |
Position of first quartile = item = item = 7th item
In c.f. column, 8 is just greater than 7 so its corresponding class is 20-30.
∴ L = 20, f = 5, c.f. = 3, i = 10
Now, we know,
Q1 = L + × i
or, Q1 = 20 + × 10
∴ Q1 = 28
Position of third quartile = item = item = 21th item
In c.f. column, corresponding class of 21 is 50-60.
∴ L = 50, f = 4, c.f. = 17, i = 10
Now, we know,
Q3 = L + × i
or, Q3 = 50 + × 10
∴ Q3 = 60
Finally,
QD = = = 16
Coefficient of quartile deviation = = = 0.36