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प्रश्न
The marks obtained (out of 100) by a class of 80 students are given below:
| Marks | Number of students |
| 10 – 20 | 6 |
| 20 – 30 | 17 |
| 30 – 50 | 15 |
| 50 – 70 | 16 |
| 70 – 100 | 26 |
Construct a histogram to represent the data above.
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उत्तर
See the given table, the class intervals are of unequal width.
So, we calculate the adjusted frequency for each class.
Now, minimum size = 20 – 10 = 10
The formula of adjusted frequencies are:
Adjusted frequency = `("Minimum class" - "size")/("Class" - "size") xx` Frequency of the class
Now, the modified table for frequency distribution is given by:
| Marks | Numbers of students (Frequency) |
Adjusted frequency |
| 10 – 20 | 6 | `10/10 xx 6 = 6` |
| 20 – 30 | 17 | `10/10 xx 17 = 17` |
| 30 – 50 | 15 | `10/20 xx 15 = 15/2 = 7.5` |
| 50 – 70 | 16 | `10/20 xx 16 = 16/2 = 8` |
| 70 – 100 | 26 | `10/30 xx 26 = 26/3 = 8.67` |
Now, let’s construct rectangles with class limits as base and respective adjusted frequencies as height

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संबंधित प्रश्न
The following bar graph (Fig. 23. 1 4) represents the heights (in cm) of 50 students of Class XI of a particular school. Study the graph and answer the following questions:

(i) What percentage of the total number of students have their heights more than 149cm?
(ii) How many students in the class are in the range of maximum height of the class?
(iii) The school wants to provide a particular type of tonic to each student below the height
of 150 cm to improve his height. If the cost of the tonic for each student comes out to be Rs. 55, how much amount of money is required?
(iv) How many students are in the range of shortest height of the class?
(v) State whether true or false:
a. There are 9 students in the class whose heights are in the range of 155 - 159 cm.
b. Maximum height (in cm) of a student in the class is 17.
c. There are 29 students in the class whose heights are in the range of 145- 154 cm.
d. Minimum height (in cm) of a student is the class is in the range of 140 – 144 cms.
e. The number of students in the class having their heights less than 150 cm is 12.
f. There are 14 students each of whom has height more than 154. cm.
Read the bar graph given in Fig. 23.21 and answer the following questions:
(i) What is the information given by the bar graph?
(ii) What is the number of families having 6 members?
(iii) How many members per family are there in the maximum number of families? Also tell the number of such families.
(iv) What are the number of members per family for which the number of families are equal? Also, tell the number of such families?
The following table shows the daily production of T. V. sets in an industry for 7 days of a week:
| Day | Mon | Tue | Wed | Thurs | Fri | Sat | Sun |
| Number of T.V. Sets | 300 | 400 | 150 | 250 | 100 | 350 | 200 |
Represent the above information by a pictograph .
The population of Delhi State in different census years is as given below:
| Census year | 1961 | 1971 | 1981 | 1991 | 2001 |
| Population in Lakhs | 30 | 55 | 70 | 110 | 150 |
Construct a histogram for the following data:
| Monthly School fee (in Rs): |
30-60 | 60-90 | 90-120 | 120-150 | 150-180 | 180-210 | 210-240 |
| No of Schools | 5 | 12 | 14 | 18 | 10 | 9 | 4 |
Which one of the following is not the graphical representation of statistical data:
Draw frequency polygons for each of the following frequency distribution:
(a) using histogram
(b) without using histogram
|
C.I |
10 - 30 |
30 - 50 |
50 - 70 | 70 - 90 | 90 - 110 | 110 - 130 | 130 - 150 |
| ƒ | 4 | 7 | 5 | 9 | 5 | 6 | 4 |
Construct a frequency polygon for the following distribution:
| Class-intervals | 0-4 | 4 - 8 | 8 - 12 | 12 - 16 | 16 - 20 | 20 - 24 |
| Frequency | 4 | 7 | 10 | 15 | 11 | 6 |
Mr. Kapoor compares the prices (in Rs.) of different items at two different shops A and B. Examine the following table carefully and represent the data by a double bar graph.
| Items | Price (in ₹) at the shop A | Price (in ₹) at the shop B |
|
Tea-set |
900 | 950 |
|
Mixie |
700 | 800 |
|
Coffee-maker |
600 | 700 |
|
Dinner set |
600 | 500 |
The expenditure of a family on different heads in a month is given below:
| Head | Food | Education | Clothing | House Rent | Others | Savings |
| Expenditure (in Rs) |
4000 | 2500 | 1000 | 3500 | 2500 | 1500 |
Draw a bar graph to represent the data above.
