Advertisements
Advertisements
Question
The time taken, in seconds, to solve a problem for each of 25 persons is as follows:
| 16 | 20 | 26 | 27 | 28 |
| 30 | 33 | 37 | 38 | 40 |
| 42 | 43 | 46 | 46 | 47 |
| 48 | 49 | 50 | 53 | 58 |
| 59 | 60 | 64 | 52 | 20 |
(i) Construct a frequency distribution for these data using a class interval of 10 seconds.
(ii) In a school the weekly pocket money of 50 students is as follow's:
| Weekly pocket money (₹) | No. of student |
| 40 - 50 | 2 |
| 59 - 60 | 8 |
| 60 - 70 | 12 |
| 70 - 80 | 14 |
| 80 - 90 | 8 |
| 90 - 100 | 6 |
Draw a histogram and a frequency polygon on the same graph. Find mode from the graph.
Advertisements
Solution
(i) Frequency table
| Time (in seconds) |
Tally marks | Frequency |
| 10 - 20 | I | 1 |
| 20 - 30 | IIIII | 5 |
| 30 - 40 | I I I I | 4 |
| 40 - 50 | IIII I I I I | 8 |
| 50 - 60 | IIIII | 5 |
| 60 - 70 | I I | 2 |
Histogram representing the time taken in seconds, to solve. A problem for each of 25 persons.
(ii) Frequency distribution table is
| Weekly pocket money (in ₹) | Class Marks | No. of Students |
| 40 - 50 | 45 | 2 |
| 50 - 60 | 55 | 8 |
| 60 - 70 | 65 | 12 |
| 70 - 80 | 75 | 14 |
| 80 - 90 | 85 | 8 |
| 90 - 100 | 95 | 6 |
Draw the histogram and frequency polygon on the graph.
Now, in the highest rectangle, draw two straight line AB and CD from the corners of the rectangle on either sides of the highest rectangle to opposite corners of the highest rectangle. They intersect P. Draw PR X-axis, then abscissa of the point prepresents ₹ 72·5.
Hence, the required mode is ₹72·5.
RELATED QUESTIONS
Observe the following frequency polygon and write the answers of the questions below it.
- Which class has the maximum number of students?
- Write the classes having zero frequency.
- What is the class-mark of the class, having frequency of 50 students?
- Write the lower and upper class limits of the class whose class mark is 85.
- How many students are in the class 80-90?
| Result (Percentage) | 30 - 40 | 40 - 50 | 50 - 60 | 60 -70 | 70 - 80 | 80 - 90 | 90 - 100 |
| No. of students | 7 | 33 | 45 | 65 | 47 | 18 | 5 |
Given below is the frequency distribution of the heights of 50 students of a class:
| Class interval: | 140−145 | 145−150 | 150−155 | 155−160 | 160−165 |
| Frequency: | 8 | 12 | 18 | 10 | 5 |
Draw a histogram representing the above data.
Find the lower quartile, the upper quartile, the interquartile range and the semi-interquartile range for the following frequency distributions:
| Shoe size | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
| Frequency | 8 | 1 | 7 | 14 | 11 | 5 | 4 |
Construct histograms for following frequency distribution:
| Class Interval | 130-140 | 140-150 | 150-160 | 160-170 | 170-180 |
| Frequency | 24 | 16 | 29 | 20 | 11 |
Following table present educational level (middle stage) of females in Arunachal pradesh according to 1981 census:
| Age group | Number of females (to the nearest ten) |
| 10 - 14 | 300 |
| 15 - 19 | 980 |
| 20 - 24 | 800 |
| 25 - 29 | 380 |
| 30 - 34 | 290 |
Draw a histogram to represent the above data.
Construct a histogram from the following distribution of total marks of 40 students in a class.
| Marks | 90 − 110 | 110 − 130 | 130 − 150 | 150 − 170 | 170 − 190 | 190 − 210 |
| No. of Students | 9 | 5 | 10 | 7 | 4 | 6 |
Histogram shows the number of people owning the different number of books. Answer the question based on it.
The number of people having books more than 20 and less than 40 is ______.
The top speeds of thirty different land animals have been organised into a frequency table. Draw a histogram for the given data.
| Maximum Speed (km/h) | Frequency |
| 10 – 20 | 5 |
| 20 – 30 | 5 |
| 30 – 40 | 10 |
| 40 – 50 | 8 |
| 50 – 60 | 0 |
| 60 – 70 | 2 |
The below histogram shows the number of literate females in the age group of 10 to 40 years in a town.
- Write the classes assuming all the classes are of equal width.
- What is the classes width?
- In which age group are literate females the least?
- In which age group is the number of literate females the highest?
