Advertisements
Advertisements
Question
The marks obtained by 50 students in Mathematics are given below.
(i) Make a frequency distribution table taking a class size of 10 marks
(ii) Draw a histogram and a frequency polygon.
| 52 | 33 | 56 | 52 | 44 | 59 | 47 | 61 | 49 | 61 |
| 47 | 52 | 67 | 39 | 89 | 57 | 64 | 58 | 63 | 65 |
| 32 | 64 | 50 | 54 | 42 | 48 | 22 | 37 | 59 | 63 |
| 36 | 35 | 48 | 48 | 55 | 62 | 74 | 43 | 41 | 51 |
| 08 | 71 | 30 | 18 | 43 | 28 | 20 | 40 | 58 | 49 |
Solution
Maximum marks obtained = 89
Minimum marks obtained = 08
Range = Maximum marks – Minimim marks
= 89 – 08
= 81
Taking the class size = 10, then
Number of possible intervals = `"Range"/"Class size"`
= `81/10`
= 8.1
= 9
| Class Interval | Tally marks | Frequency |
| 0 − 10 | I | 1 |
| 10 − 20 | I | 1 |
| 20 − 30 | III | 3 |
| 30 − 40 | IIII III | 8 |
| 40 − 50 | IIII IIII III | 13 |
| 50 − 60 | IIII IIII II | 12 |
| 60 − 70 | IIII IIII | 9 |
| 70 − 80 | II | 2 |
| 80 − 90 | I | 1 |
| Total | 50 | 50 |
Now we have the continuous frequency table.
| Class Intervals | 0 − 10 | 10 − 20 | 20 − 30 | 30 − 40 | 40 − 50 | 50 − 60 | 60 − 70 | 70 − 80 | 80 − 90 |
| Frequency | 1 | 1 | 3 | 8 | 13 | 12 | 9 | 2 | 1 |
We will draw the histogram taking class interval in x-axis and frequency in y-axis as follows.
APPEARS IN
RELATED QUESTIONS
The weekly wages (in Rs) of 30 workers in a factory are.
830, 835, 890, 810, 835, 836, 869, 845, 898, 890, 820, 860, 832, 833, 855, 845, 804, 808, 812, 840, 885, 835, 835, 836, 878, 840, 868, 890, 806, 840
Using tally marks make a frequency table with intervals as 800 − 810, 810 − 820 and so on.
In the following table, the investment made by 210 families is shown. Present it in the form of a histogram.
|
Investment
(Thousand Rupees) |
10 - 15 | 15 - 20 | 20 - 25 | 25 - 30 | 30 - 35 |
| No. of families | 30 | 50 | 60 | 55 | 15 |
Number of workshops organized by a school in different areas during the last five years are as follows:
| Years | No. of workshops |
| 1995−1996 | 25 |
| 1996−1997 | 30 |
| 1997−1998 | 42 |
| 1998−1999 | 50 |
| 1999−2000 | 65 |
Draw a histogram representing the above data.
Construct a frequency polygon without using a histogram for the following frequency distribution :
| Class Mark | 10 | 15 | 20 | 25 | 30 | 35 | 40 |
| Frequency | 4 | 20 | 40 | 45 | 30 | 25 | 5 |
Draw a histogram and frequency polygon to represent the following data (on the same scale) which shows the monthly cost of living index of a city in a period of 2 years:
| Cost of living Index | Number of months |
| 440 - 460 | 2 |
| 460 - 480 | 4 |
| 480 - 500 | 3 |
| 500 - 520 | 5 |
| 520 - 540 | 3 |
| 540 - 560 | 2 |
| 560 - 580 | 1 |
| 580 - 600 | 4 |
| Total | 24 |
In a village, there are 570 people who have cell phones. An NGO survey their cell phone usage. Based on this survey a histogram is drawn
Are people using cell phone for less than 1 hour?
The number of people having books more than 20 and less than 40 is ______.
The following pictorial representation of data is a histogram.
Look at the histogram below and answer the questions that follow.
- How many students have height more than or equal to 135 cm but less than 150 cm?
- Which class interval has the least number of students?
- What is the class size?
- How many students have height less than 140 cm?
Use graph paper for this question. Estimate the mode of the given distribution by plotting a histogram. [Take 2 cm = 10 marks along one axis and 2 cm = 5 students along the other axis]
| Daily wages (in ₹) | 30 - 40 | 40 - 50 | 50 - 60 | 60 - 70 | 70 - 80 |
| No. of Workers | 6 | 12 | 20 | 15 | 9 |
