Advertisements
Advertisements
Question
If class mark is 10 and class width is 6 then find the class.
Advertisements
Solution
Let x be the upper class limit and y the lower class limit.
class mark = 10 ..[given]
class mark = `(x + y)/2`
10 = `(x + y)/2`
x + y = 20 ...(i)
class width = 6 ...[given]
x - y = 6 ....(ii)
Adding equation (i) and (ii)
x + y = 20
+ x - y = 6
2x = 26
x = `26/2`
x = 13
Putting the value x = 13 in equation (i),
x + y = 20
13 + y = 20
y = 20 -13
y = 7
∴ the class is 7-13.
APPEARS IN
RELATED QUESTIONS
For class interval 20-25 write the lower class limit and the upper class limit.
In the table given below, class-mark and frequencies are given. Construct the frequency table taking inclusive and exclusive classes.
| Class width | Frequency |
| 5 | 3 |
| 15 | 9 |
| 25 | 15 |
| 35 | 13 |
In the table given below, class-mark and frequencies are given. Construct the frequency table taking inclusive and exclusive classes.
| Class width | Frequency |
| 22 | 6 |
| 24 | 7 |
| 26 | 13 |
| 28 | 4 |
In a village, the milk was collected from 50 milkmen at a collection center in litres as given below:
27, 75, 5, 99, 70, 12, 15, 20, 30, 35, 45, 80, 77, 90, 92, 72, 4, 33, 22, 15, 20, 28, 29, 14, 16, 20, 72, 81, 85, 10, 16, 9, 25, 23, 26, 46, 55, 56, 66, 67, 51, 57, 44, 43, 6, 65, 42, 36, 7, 35.
By taking suitable classes, prepare grouped frequency distribution table.
What is the upper class limit for the class 25-35?
The value of π up to 50 decimal place is
3.14159265358979323846264338327950288419716939937510
(i) Make a frequency distribution table of digits from 0 to 9 after the decimal place.
(ii) Which are the most and least occurring digits?
Given below are the marks obtained by 30 students in an examination:
| 08 | 17 | 33 | 41 | 47 | 23 | 20 | 34 |
| 09 | 18 | 42 | 14 | 30 | 19 | 29 | 11 |
| 36 | 48 | 40 | 24 | 22 | 02 | 16 | 21 |
| 15 | 32 | 47 | 44 | 33 | 01 |
Taking class intervals 1-10, 11-20, ....., 41-50; make a frequency table for the above distribution.
Construct a cumulative frequency distribution table from the frequency table given below:
| Class Interval | Frequency |
| 0 -8 | 9 |
| 8 - 16 | 13 |
| 16 - 24 | 12 |
| 24 - 32 | 7 |
| 32 - 40 | 15 |
Given below are the marks obtained by 30 students in an examination:
|
08 |
17 |
33 |
41 |
47 |
23 |
20 |
34 |
|
09 |
18 |
42 |
14 |
30 |
19 |
29 |
11 |
|
36 |
48 |
40 |
24 |
22 |
02 |
16 |
21 |
|
15 |
32 |
47 |
44 |
33 |
01 |
Taking class intervals 1 - 10, 11 - 20, ....., 41 - 50; make a frequency table for the above distribution.
A dice was cast 40 times and each score noted is given below. Draw up a frequency table for this data.
3, 2, 5, 6, 4, 2, 3, 1, 6, 6, 2, 3, 5, 3, 5, 3, 4, 2, 4, 5, 4, 2, 6, 3, 3, 2, 4, 3, 3, 4, 1, 4, 3, 3, 2, 2, 5, 3, 3, 4
Observe the given frequency table to answer the following:
| Class Interval | 20 - 24 | 25 29 | 30 - 34 | 35 - 39 | 40 - 44 | 45 - 49 |
| Frequency | 6 | 12 | 10 | 15 | 9 | 2 |
a. The true class limits of the fifth class.
b. The size of the second class.
c. The class boundaries of the fourth class.
d. The upper and lower limits of the sixth class.
e. The class mark of the third class.
The upper limit of the class interval (25 - 35) is _____________
Represent the following data in ungrouped frequency table which gives the number of children in 25 families.
1, 3, 0, 2, 5, 2, 3, 4, 1, 0, 5, 4, 3, 1, 3, 2, 5, 2, 1, 1, 2, 6, 2, 1, 4
In the class interval 26 – 33, 33 is known as ______.
The difference between the upper and lower limit of a class interval is called the ______ of the class interval.
In the class intervals 10 – 20, 20 – 30, etc., respectively, 20 lies in the class ______.
If the fifth class interval is 60 – 65, fourth class interval is 55 – 60, then the first-class interval is 45 – 50.
The class size of the class interval 60 – 68 is 8.
The weights (in kg) of 30 students of a class are:
39, 38, 36, 38, 40, 42, 43, 44, 33, 33, 31, 45, 46, 38, 37, 31, 30, 39, 41, 41, 46, 36, 35, 34, 39, 43, 32, 37, 29, 26.
Prepare a frequency distribution table using one class interval as (30 – 35), 35 not included.
- Which class has the least frequency?
- Which class has the maximum frequency?
