2. The following table shows marks attained by 100 form three students in a mathematics test. calculate: i) median, ii)lower quarntile, iii) upper quartile, iv) interquartile range.
|
Class Marks |
1-10 |
11-20 |
21-30 |
31-40 |
41-50 |
51-60 |
61-70 |
71-80 |
81-90 |
91-100 |
|
Frequency |
2 |
7 |
9 |
11 |
13 |
16 |
16 |
15 |
8 |
3 |
| CLASS | BOUNDARIES | f | cf |
| 1-10 | 0.5-10.5 | 2 | |
| 11-20 | 10.5-20.5 | 7 | |
| 21-30 | 20.5-30.5 | 9 | |
| 31-40 | 30.5-40.5 | 11 | |
| 41-50 | 40.5-50.5 | 13 | |
| 51-60 | 50.5-60.5 | 16 | |
| 61-70 | 60.5-70.5 | 16 | |
| 71-80 | 70.5-80.5 | 15 | |
| 81-90 | 80.5-90.5 | 8 | |
| 91-100 | 90.5-100.5 | 3 |
| Indentify the median class. the median class is |