CBSE 10 Mathematics Statistics Practice Paper 12
1. The marks obtained by 30 students of Class X of a certain school in a Mathematics paper consisting of 100 marks are presented in table below. Find the mean of the marks obtained by the students.| Marks Obtained (\(x_i\)) | 10 | 20 | 36 | 40 | 50 | 56 | 60 | 70 | 72 | 80 | 88 | 92 | 95 | |
| Number of students \((f_i)\) | 1 | 1 | 3 | 4 | 3 | 2 | 4 | 4 | 1 | 1 | 2 | 3 | 1 |
| Percentage of female teachers | 15 - 25 | 25 - 35 | 35 - 45 | 45 - 55 | 55 - 65 | 65 - 75 | 75 - 85 | |
| Number of States/U.T. | 6 | 11 | 7 | 4 | 4 | 2 | 1 |
| Daily pocketallowance (in Rs) | 11 - 13 | 13 - 15 | 15 - 17 | 17 - 19 | 19 - 21 | 21 - 23 | 23 - 25 | |
| Number of children | 7 | 6 | 9 | 13 | f | 5 | 4 |
| Family size | 1 - 3 | 3 - 5 | 5 - 7 | 7 - 9 | 9 - 11 | |
| Number of families | 7 | 8 | 2 | 2 | 1 |
| Age (in years) | 5 - 15 | 15 - 25 | 25 - 35 | 35 - 45 | 45 - 55 | 55 - 65 | |
| Number of patients | 6 | 11 | 21 | 23 | 14 | 5 |
| Number of cars | 0 - 10 | 10 - 20 | 20 - 30 | 30 - 40 | 40 - 50 | 50 - 60 | 60 - 70 | 70 - 80 | |
| Frequency | 7 | 14 | 13 | 12 | 20 | 11 | 15 | 8 |
| Monthly consumption (in units) | Number of consumers | |
| 65 - 85 | 4 | |
| 85 - 105 | 5 | |
| 105 - 125 | 13 | |
| 125 - 145 | 20 | |
| 145 - 165 | 14 | |
| 165 - 185 | 8 | |
| 185 - 205 | 4 |
| Class interval | Frequency | |
| 0 - 10 | 5 | |
| 10 - 20 | x | |
| 20 - 30 | 20 | |
| 30 - 40 | 15 | |
| 40 - 50 | y | |
| 50 - 60 | 5 | |
| Total | 60 |
| 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 |
Find the median length of the leaves.
10. The following table gives the distribution of the life time of 400 neon lamps :
| Life time (in hours) | life time of a lamp | |
| 1500 - 2000 | 14 | |
| 2000 - 2500 | 56 | |
| 2500 - 3000 | 60 | |
| 3000 - 3500 | 86 | |
| 3500 - 4000 | 74 | |
| 4000 - 4500 | 62 | |
| 4500 - 5000 | 48 |
