export declare function toRNumericArray(data: unknown, functionName: string): number[];
export declare function toRNumber(value: unknown, functionName: string): number;
export declare function sortedRNumbers(data: unknown, functionName: string): number[];
export declare function medianOfSorted(values: number[], low?: boolean, high?: boolean): number;
export declare function sampleVariance(values: number[]): number;
export declare function sampleCovariance(left: number[], right: number[], functionName: string): number;