/**
 * 根据条件求平均数
 * @param {Array} array
 * @param {Function | number} fn
 */
export {};
declare global {
    interface Math {
        averageBy(array: {
            map: (arg0: any) => {
                reduce: (arg0: (acc: any, val: any) => any, arg1: number) => number;
            };
            length: number;
        }, fn: string | number | Function): number;
    }
}