Given a list of numbers, return the median value.
The median value of the list `[5, 15, 10, 7]` is `8.5`.
5, 15, 10, 7
Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.

### Instruction:
Given a list of numbers, return the median value.

### Input:
5, 15, 10, 7

### Response:
The median value of the list `[5, 15, 10, 7]` is `8.5`.