/**
 * Calculates the arithmetic mean of an array of numbers
 * @param  {number[]} numbers - Array of numbers to average
 * @returns {number} The arithmetic mean, returns 0 for empty array
 * @example
 * average([1, 2, 3]); // 2
 * average([10, 20]); // 15
 * average([]); // 0
 */
export declare const average: (numbers: number[]) => number;