/**
 * Advanced math and statistics utilities
 * These are enhanced utilities beyond standard Lodash
 */
/**
 * Computes the mean (average) of the values in array.
 *
 * @param array - The array to compute the mean of
 * @returns Returns the mean value
 *
 * @example
 * mean([4, 2, 8, 6]);
 * // => 5
 *
 * mean([]);
 * // => undefined
 */
export declare function mean(array: readonly number[]): number | undefined;
/**
 * Computes the median of the values in array.
 *
 * @param array - The array to compute the median of
 * @returns Returns the median value
 *
 * @example
 * median([4, 2, 8, 6]);
 * // => 5
 *
 * median([4, 2, 8, 6, 10]);
 * // => 6
 */
export declare function median(array: readonly number[]): number | undefined;
/**
 * Computes the mode (most frequent value) of the values in array.
 *
 * @param array - The array to compute the mode of
 * @returns Returns an array of the most frequent values
 *
 * @example
 * mode([4, 2, 8, 6, 2, 4, 2]);
 * // => [2]
 *
 * mode([4, 2, 8, 6, 2, 4]);
 * // => [2, 4]
 */
export declare function mode(array: readonly number[]): number[];
/**
 * Computes the standard deviation of the values in array.
 *
 * @param array - The array to compute the standard deviation of
 * @param sample - Whether to use sample standard deviation (default: false for population)
 * @returns Returns the standard deviation
 *
 * @example
 * standardDeviation([2, 4, 4, 4, 5, 5, 7, 9]);
 * // => 2
 *
 * standardDeviation([2, 4, 4, 4, 5, 5, 7, 9], true);
 * // => 2.138
 */
export declare function standardDeviation(array: readonly number[], sample?: boolean): number | undefined;
/**
 * Computes the variance of the values in array.
 *
 * @param array - The array to compute the variance of
 * @param sample - Whether to use sample variance (default: false for population)
 * @returns Returns the variance
 *
 * @example
 * variance([2, 4, 4, 4, 5, 5, 7, 9]);
 * // => 4
 */
export declare function variance(array: readonly number[], sample?: boolean): number | undefined;
/**
 * Computes the percentile of the values in array.
 *
 * @param array - The array to compute the percentile of
 * @param percentile - The percentile to compute (0-100)
 * @returns Returns the percentile value
 *
 * @example
 * percentile([1, 2, 3, 4, 5], 50);
 * // => 3
 *
 * percentile([1, 2, 3, 4, 5, 6], 75);
 * // => 4.75
 */
export declare function percentile(array: readonly number[], percentile: number): number | undefined;
/**
 * Computes the range (difference between max and min) of the values in array.
 *
 * @param array - The array to compute the range of
 * @returns Returns the range
 *
 * @example
 * rangeOfValues([4, 2, 8, 6]);
 * // => 6
 */
export declare function rangeOfValues(array: readonly number[]): number | undefined;
/**
 * Computes the geometric mean of the values in array.
 *
 * @param array - The array to compute the geometric mean of
 * @returns Returns the geometric mean
 *
 * @example
 * geometricMean([2, 8]);
 * // => 4
 *
 * geometricMean([4, 1, 1/32]);
 * // => 0.5
 */
export declare function geometricMean(array: readonly number[]): number | undefined;
/**
 * Computes the harmonic mean of the values in array.
 *
 * @param array - The array to compute the harmonic mean of
 * @returns Returns the harmonic mean
 *
 * @example
 * harmonicMean([2, 3, 4]);
 * // => 2.769...
 */
export declare function harmonicMean(array: readonly number[]): number | undefined;