The masses, in kilograms (kg), of 20 parcels in a delivery van are shown below.
| 5 | 12 | 23 | 35 | 9 |
| 16 | 18 | 30 | 15 | 11 |
| 7 | 14 | 19 | 32 | 18 |
| 8 | 21 | 22 | 27 | 25 |
Draw an ordered stem and leaf diagram to show this information. You must include a key.
Work out the median mass.
Another parcel is added with a mass of 45 kg. Leo says: "This means the median mass will increase." Is Leo correct? You must explain your answer.
