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प्रश्न
Mark the correct alternative in each of the following: Tally marks are used to find
विकल्प
class intervals
range
frequency
upper limits
उत्तर
Tally marks are used to find the frequencies.
APPEARS IN
संबंधित प्रश्न
The blood groups of 30 students of Class VIII are recorded as follows:-
A, B, O, O, AB, O, A, O, B, A, O, B, A, O, O, A, AB, O, A, A, O, O, AB, B, A, O, B, A, B, O.
Represent this data in the form of a frequency distribution table. Which is the most common, and which is the rarest, blood group among these students?
The distance (in km) of 40 engineers from their residence to their place of work were found as follows:-
| 5 | 3 | 10 | 20 | 25 | 11 | 13 | 7 | 12 | 31 |
| 19 | 10 | 12 | 17 | 18 | 11 | 32 | 17 | 16 | 2 |
| 7 | 9 | 7 | 8 | 3 | 5 | 12 | 15 | 18 | 3 |
| 12 | 14 | 2 | 9 | 6 | 15 | 15 | 7 | 6 | 12 |
Construct a grouped frequency distribution table with class size 5 for the data given above taking the first interval as 0-5 (5 not included). What main features do you observe from this tabular representation?
The heights of 50 students, measured to the nearest centimeters, have been found to be as follows:-
| 161 | 150 | 154 | 165 | 168 | 161 | 154 | 162 | 150 | 151 |
| 162 | 164 | 171 | 165 | 158 | 154 | 156 | 172 | 160 | 170 |
| 153 | 159 | 161 | 170 | 162 | 165 | 166 | 168 | 165 | 164 |
| 154 | 152 | 153 | 156 | 158 | 162 | 160 | 161 | 173 | 166 |
| 161 | 159 | 162 | 167 | 168 | 159 | 158 | 153 | 154 | 159 |
(i) Represent the data given above by a grouped frequency distribution table, taking the class intervals as 160 - 165, 165 - 170, etc.
(ii) What can you conclude bout their heights from the table?
The marks scored by 40 students of class IX in mathematics are given below:
81, 55, 68, 79, 85, 43, 29, 68, 54, 73, 47, 35, 72, 64, 95, 44, 50, 77, 64, 35, 79, 52, 45, 54, 70,
83, 62, 64, 72, 92, 84, 76, 63, 43, 54, 38, 73, 68, 52, 54.
Prepare a frequency distribution with class size of 10 marks.
Three coins were tossed 30 times. Each time the number of head occurring was noted down
as follows:
0 1 2 2 1 2 3 1 3 0
1 3 1 1 2 2 0 1 2 1
3 0 0 1 1 2 3 2 2 0
Given below are the cumulative frequencies showing the weights of 685 students of a school. Prepare a frequency distribution table.
| Weight (in kg) | No. of students |
| Below 25 | 0 |
| Below 30 | 24 |
| Below 35 | 78 |
| Below 40 | 183 |
| Below 45 | 294 |
| Below 50 | 408 |
| Below 55 | 543 |
| Below 60 | 621 |
| Below 65 | 674 |
| Below 70 | 685 |
The mid-value of a class interval is 42. If the class size is 10, then the upper and lower limits of the class are:
The width of each of nine classes in a frequency distribution is 2.5 and the lower class boundary of the lowest class 10.6. Then the upper class boundary of the highest class is
For drawing a frequency polygon of a continous frequency distribution, we plot the points whose ordinates are the frequencies of the respective classes and abcissae are respectively ______.
30 children were asked about the number of hours they watched TV programmes last week. The results are recorded as under:
| Number of hours | 0 – 5 | 5 – 10 | 10 – 15 | 15 – 20 |
| Frequency | 8 | 16 | 4 | 2 |
Can we say that the number of children who watched TV for 10 or more hours a week is 22? Justify your answer.
