Advertisements
Advertisements
Question
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.
Advertisements
Solution
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
APPEARS IN
RELATED QUESTIONS
The following table gives the life times of 400 neon lamps:-
| Life time (in hours) | Number of lamps |
| 300 - 400 | 14 |
| 400 - 500 | 56 |
| 500 - 600 | 60 |
| 600 - 700 | 86 |
| 700 - 800 | 74 |
| 800 - 900 | 62 |
| 900 - 1000 | 48 |
- Represent the given information with the help of a histogram.
- How many lamps have a life time of more than 700 hours?
Read the bar graph given in Fig. 23.19 and answer the following questions:
(i) What information is given by the bar graph?
(ii) In which years the areas under the sugarcane crop were the maximum and the minimum?
(iii) State whether true or false:
The area under the sugarcane crop in the year 1982 - 83 is three times that of the year 1950 - 51
Read the following bar graph and answer the following questions:
(i) What information is given by the bar graph?
(ii) In which year the export is minimum?
(iii)In which year the import is maximum?
(iv)In which year the difference of the values of export and import is maximum?
The following tables gives the quantity of goods (in crore tonnes)
| Year | 1950-51 | 1960-61 | 1965-66 | 1970-71 | 1980-81 | 1982-83 |
| Quantity of Goods (in crore tonnes) |
9 | 16 | 20 | 20 | 22 | 26 |
Explain through the bar graph if the quantity of goods carried by the Indian Railways in 1965-66 is more than double the quantity of goods carried in the year 1950-51.
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 |
In a frequency distribution, ogives are graphical representation of
The following tables show the mode of transport used by boys and girls for going to the same school.
| Bus | Bicycle | Walking | Other sources | |
|
Number of boys |
80 | 60 | 20 | 85 |
|
Number of girls |
90 | 75 | 35 | 60 |
Draw a double bar graph representing the above data.
The following table shows the market position of different brands of tea-leaves.
| Brand | A | B | C | D | others |
| % of Buyers | 35 | 20 | 20 | 15 | 10 |
Draw it-pie-chart to represent the above information.
In a diagnostic test in mathematics given to students, the following marks (out of 100) are recorded:
46, 52, 48, 11, 41, 62, 54, 53, 96, 40, 98, 44
Which ‘average’ will be a good representative of the above data and why?
Draw a histogram of the following distribution:
| Heights (in cm) | Number of students |
| 150 – 153 | 7 |
| 153 – 156 | 8 |
| 156 – 159 | 14 |
| 159 – 162 | 10 |
| 162 – 165 | 6 |
| 165 – 168 | 5 |
