6 Seventy samples of fertiliser were collected and the nitrogen content was measured for each sample. The cumulative frequency distribution is shown in the table below.
| Nitrogen content | \(\leqslant 3.5\) | \(\leqslant 3.8\) | \(\leqslant 4.0\) | \(\leqslant 4.2\) | \(\leqslant 4.5\) | \(\leqslant 4.8\) |
| Cumulative frequency | 0 | 6 | 18 | 41 | 62 | 70 |
- On graph paper draw a cumulative frequency graph to represent the data.
- Estimate the percentage of samples with a nitrogen content greater than 4.4.
- Estimate the median.
- Construct the frequency table for these results and draw a histogram on graph paper.