Advertisements
Advertisements
Question
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 |
Advertisements
Solution
The frequency polygon is shown in the following figure
Steps:
(i) Drawing a histogram for the given data.
(ii) Marking the mid-point at the top of each rectangle of the histogram drawn.
(iii) Also, marking mid-point of the immediately lower class-interval and mid-point of the immediately higher class-interval.
(iv) Joining the consecutive mid-points marked by straight lines to obtain the required frequency polygon.
APPEARS IN
RELATED QUESTIONS
The length of 40 leaves of a plant are measured correct to one millimetre, and the obtained data is represented in the following table:-
| Length (in mm) | Number of leaves |
| 118 - 126 | 3 |
| 127 - 135 | 5 |
| 136 - 144 | 9 |
| 145 - 153 | 12 |
| 154 - 162 | 5 |
| 163 - 171 | 4 |
| 172 - 180 | 2 |
- Draw a histogram to represent the given data. [Hint: First make the class intervals continuous]
- Is there any other suitable graphical representation for the same data?
- Is it correct to conclude that the maximum number of leaves are 153 mm long? Why?
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. 23.21 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 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.
Draw a histogram for the daily earnings of 30 drug stores in the following table:
| Daily earning (in Rs): |
450-500 | 500-550 | 550-600 | 600-650 | 650-700 |
| Number of Stores: | 16 | 10 | 7 | 3 | 1 |
Which one of the following is not the graphical representation of statistical data:
In a histogram, each class rectangle is constructed with base as
The percentage of marks obtained, in different subjects by Ashok Sharma (in an examination) is given below. Draw a bar graph to represent it.
| English | Hindi | Maths | Science | Social Studies |
| 85 | 60 | 35 | 50 | 70 |
For the following table, draw a bar-graph
| A | B | C | D | E | F |
| 230 | 400 | 350 | 200 | 380 | 160 |
Mr. Mirza’s monthly income is Rs. 7,200. He spends Rs. 1,800 on rent, Rs. 2,700 on food, Rs. 900 on the education of his children; Rs. 1,200 on Other things and saves the rest.
Draw a pie-chart to represent it.
