Here is a list of seven numbers. One of the numbers is hidden.
| 12 | 6 | 7 | 10 | 7 | 9 | ? |
The mean of the numbers is 10.
Find the value of the hidden number and hence find the range of the seven numbers.
201 exam-style questions on Edexcel GCSE Maths Averages. Each one has a worked solution and a mark scheme showing where the marks go.