Неизвестная ошибка

C:/Users/Admin/CLionProjects/pr1/main.cpp:38: undefined reference to `experiment(int*, unsigned int, unsigned int, double*, double*)'
collect2.exe: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.

#include <iostream>
#include "statistics.h"
#include "experiment.h"
#include <stdlib.h>
#include <fstream>
#include <iomanip>
 
using namespace std;
 
int main() {
    int n_min{}, n_max{}, step{}, z{};
    cout << "Enter a space separates:" << endl;
    cout << "N_min = ";
    cin >> n_min;
    cout << "N_max = ";
    cin >> n_max;
    cout << "Step = ";
    cin >> step;
    cout << "Number of repetitions Z = ";
    cin >> z;
    cout << endl;
 
    int n{(n_max - n_min) / step + 1};
    int *arguments{new int[n]};
    double *mean{new double[n]}, *stds{new double[n]};
 
    for (size_t i{}; i < n; ++i){
        arguments[i] = n_min + i * step;
    }
    cout << "argument = [";
 
    for (size_t i{}; i < n; ++i) {
        cout << arguments[i] << (i == n - 1 ? "" : ",");
    }
    cout << "]" << endl;
    cout << endl;
 
    experiment(arguments, n, z, mean, stds);
 
    ofstream fout{"experiment.txt"};
 
    if(!fout.good()) {
        cerr << "File creation error!" << endl;
        fout.close();
    }
 
    cout << setw(7) << "number" << "|" << setw(9) << "argument" << "|"
         << setw(8) << "mean" << "|" << setw(8) << "stds, 10^-3" << endl;
    fout << setw(7)<< "number" << "|" << setw(9) << "argument" << "|"
         << setw(8) << "mean" << "|" << setw(8) << "stds, 10^-3" << endl;
    for (size_t i{}; i < n; ++i) {
        cout << setw(7) << i + 1 << "|" << setw(9) << arguments[i] << "|"
             << setw(8) << fixed << setprecision(4) << mean[i] << "|" << setw(8) << 1000 * stds[i] << endl;
        fout << setw(7)<< i + 1 << "|" << setw(9) << arguments[i] << "|"
             << setw(8) << fixed << setprecision(4) << mean[i] << "|" << setw(8) << 1000 * stds[i] << endl;
    }
 
    fout.close();
    delete[] arguments;
    delete[] mean;
    delete[] stds;
 
    return 0;
}

#include "experiment.h"
#include <chrono>
#include <ctime>
#include "statistics.h"
 
 
int foo(int n) {
    int res{};
    for(size_t i{1}; i <= n; ++i) {
        for(size_t j{1}; j <= n; ++j) {
            res += i * j;
        }
    }
    return res;
}
 
double measureTime(int n) {
    using namespace std::chrono;
    steady_clock::time_point t1 = steady_clock::now();
 
    foo(n);
 
    steady_clock::time_point t2 = steady_clock::now();
    duration<double> time_span = duration_cast<duration<double>>(t2 - t1);
    return time_span.count();
}
 
void experiment(int *arguments, size_t n, size_t z, double *means, double *stds) {
    double *times{new double[z]};
 
    for(int i{}; i < n; ++i) {
        for(size_t j{}; j < z; ++j) {
            times[j] = measureTime(arguments[i]);
        }
        *means++ = meanTime(times, z);
        *stds++ = stdTime(times, z);
    }
    delete [] times;
}

#include <stdlib.h>
 
int foo(int);
double measureTime(int);
void experiment(int *, size_t, size_t, double *, double *);
 
#endif

#include "statistics.h"
#include <cmath>
 
double meanTime(double *times, size_t z) {
    double sum{};
    for (size_t i{}; i < z; ++i) {
        sum = sum + times[i];
    }
    return sum/z;
}
 
double stdTime(double *times, size_t z) {
    double mT{meanTime(times, z)}, sum{};
    for (size_t i{}; i < z; ++i) {
        sum += (times[i] - mT) * (times[i] - mT);
    }
    return sqrt(sum/z);
}

#include <stdlib.h>
 
double meanTime(double*, size_t);
double stdTime(double*, size_t);
 
#endif