3 The following cumulative frequency table shows the examination marks for 300 candidates in country \(A\) and 300 candidates in country \(B\).
| Mark | \(< 10\) | \(< 20\) | \(< 35\) | \(< 50\) | \(< 70\) | \(< 100\) |
| Cumulative frequency, \(A\) | 25 | 68 | 159 | 234 | 260 | 300 |
| Cumulative frequency, \(B\) | 10 | 46 | 72 | 144 | 198 | 300 |
- Without drawing a graph, show that the median for country \(B\) is higher than the median for country \(A\).
- Find the number of candidates in country \(A\) who scored between 20 and 34 marks inclusive.
- Calculate an estimate of the mean mark for candidates in country \(A\).