输入一个数组，求数组中的元素的平均值和最大，最小值?怎么用C#中编写啊?

using System;
using System.Collections.Generic;
using System.Text;

namespace _ti
{
class Program
{
static void Main(string[] args)
{
int i;
int sum=0;
int max=0;
int min=0;
int avg;
int []a=new int [5];

for ( i = 0; i < 5; i++)
{
a[i] = i;
Console.WriteLine("a[{0}]={1}",i,a[i]);

}
sum = a[0] + a[1] + a[2] + a[3] + a[4];
avg = sum / 5;
Console.WriteLine("avg={0}", avg);
max = a[0]> a[1] ? a[0] : a[1];
max = max > a[2] ? max : a[2];
max = max > a[3] ? max : a[3];
max = max > a[4] ? max : a[4];
Console.WriteLine("max={0}",max);
min = a[0] < a[1] ? a[0] : a[1];
min = min < a[2] ? min : a[2];
min = min < a[3] ? min : a[3];
min = min < a[4] ? min : a[4];
Console.WriteLine("min={0}",min);

Console.ReadLine();

}
}
}