Challenge: Working with Coroutines

Problem 1

In this problem, you are required to implement a coroutine running_average() that calculates the running average of numbers sent to it.

Requirements

• The coroutine should:
  1. Start with no numbers.
  2. Accept numbers using .send(value).
  3. After each number is sent, yield the current running average.
• If .send() is called with None, the coroutine should stop and return the final average.

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