The monthly income of a group of 320 employees in a company is given below:
| Monthly income (thousands) | No. of employees |
| 6-7 | 20 |
| 7-8 | 45 |
| 8-9 | 65 |
| 9-10 | 95 |
| 10-11 | 60 |
| 11-12 | 30 |
| 12-13 | 5 |
Draw an ogive of the given distribution on a graph paper taking 2 cm = Rs. 1000 on one axis and 2 cm = 50 employees on the other axis. From the graph determine:
(i) the median wage.
(ii) number of employee whose income is below Rs. 8500.
(iii) if salary of a senior employee is above Rs. 11500, find the number of senior employees in the company .
(iv) the upper quartile.
