Here is a list of seven numbers. One of the numbers is hidden.
| 11 | 6 | 7 | 10 | 7 | 7 | ? |
| ---- | --- | --- | ---- | --- | --- | --- |
The mean of the numbers is 9.
Find the value of the hidden number.
Hence, find the mean of the six numbers that are not hidden.
201 exam-style questions on Edexcel GCSE Maths Averages. Each one has a worked solution and a mark scheme showing where the marks go.