public class Solution {
    public double findMaxAverage(int[] nums, int k) {
        
        double sum = 0;
        
        for(int i=0; i<k; i++)
            sum += nums[i];
        
        double max = sum;
        
        for(int i=k; i<nums.length; i++)
        {
            sum += nums[i] - nums[i-k];
            max = Math.max(sum, max);
        }
        
        return max/k;        
        
    }
}