find the min and max in array of 10000 numbers using two threads

using System;
using System.Threading;
using System.Threading.Tasks;

namespace Threading
{
    class Program
    {
        private static int RandomNumber(int min, int max)
        {
            Random random = new Random();
            return random.Next(min, max);
        }
        static void Main(string[] args)
        {
            int min, max;
            int[] randomArray = new int[10000];
            for (int i = 0; i < 10000; i++)
            {
                randomArray[i] = RandomNumber(0, 10000);
            }
            //int[] randomArray = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 };
            object lockObj = new object();
            Parallel.Invoke(() =>
            {
                int min1 = randomArray[0];
                int max1 = randomArray[0];
                for (int i = 0; i <