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Exercise

Calculate an average value

We all know how to calculate an average value iteratively:

def average(nums):

    result = 0

    for num in nums:
        result += num

    return result/len(nums)

Could you provide a recursive solution? A formula for updating an average value given a new input might be handy:

$$ \bar{x} \leftarrow \frac{x_i + (n-1)\bar{x}}{n} $$

Here, \(\bar x\) stands for an average value, \(x_i\) is a new supplied value which is used to update the average, and \(n\) corresponds to the recursive call number (excluding the initial call to the function).

Instructions

100 XP
  • Provide the base case for the algorithm.
  • Define the recursive call for updating the average value.