Arrays & Array Methods (map, filter, reduce)

What statistical calculation is this reduce operation performing?

const numbers = [1, 2, 3, 4, 5];
const result = numbers.reduce((acc, curr, idx, arr) => {
  if (idx === arr.length - 1) return (acc + curr) / arr.length;
  return acc + curr;
}, 0);

Sum of all numbers
Average of all numbers
This reduce operation calculates the average (mean): 1) Accumulates sum throughout the array, 2) Checks if it's the last element using index, 3) On last element, divides total by array length, 4) Combines sum and average calculation in one pass, 5) More efficient than separate sum and division, 6) Uses array context for length calculation, 7) Common pattern for statistical operations, 8) Results in arithmetic mean of all values.
Median of all numbers
Maximum value

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