Q. 6. A survey regarding the heights ( in cm ) of 51 girls of class X of a school was conducted and the following data was obtained:
| Height ( in cm ) | Number of girls |
| Less than 140 | 4 |
| Less than 145 | 11 |
| Less than 150 | 29 |
| Less than 155 | 40 |
| Less than 160 | 46 |
| Less than 165 | 51 |
Find the median height.
Q. 7. Following is the age distribution of a group of students. Draw the cumulative & frequency polygon, cumulative & frequency curve (less than type) and hence obtain the median value.
| Age | Frequency |
| 5 – 6 | 40 |
| 6 – 7 | 56 |
| 7 – 8 | 60 |
| 8 – 9 | 66 |
| 9 – 10 | 84 |
| 10 – 11 | 96 |
| 11 – 12 | 92 |
| 12 – 13 | 80 |
| 13 – 14 | 64 |
| 14 – 15 | 44 |
| 15 – 16 | 22 |
| 16 – 17 | 22 |
Q. 8. Find the median marks from the following data:-
| Marks | 00 and above | 10 and above | 20 and above | 30 and above | 40 and above | 50 and above | 60 and above | 70 and above | 80 and above | 90 and above | 100 and above |
| Number of Students | 80 | 77 | 72 | 65 | 55 | 43 | 28 | 16 | 10 | 08 | 00 |
Q. 9. Find the mean, median and mode of the following data:
| Classes | 4 − 8 | 8 − 12 | 12 − 16 | 16 − 20 | 20 − 24 | 24 − 28 | 28 − 32 | 32 − 36 | Total |
| No. of students | 2 | 12 | 15 | 25 | 18 | 12 | 13 | 3 | 100 |
Q. 10. The following frequency distribution gives the monthly consumption of electricity 68 consumer of a locality. Find the median, mean and mode of the data and compare them.
| Monthly Consumption of electricit | No. of Consumers |
| 65 – 85 | 4 |
| 85 – 105 | 5 |
| 105 – 125 | 13 |
| 125 – 145 | 20 |
| 145 – 165 | 14 |
| 165 – 185 | 8 |
| 185 – 205 | 4 |
