
    Create a function that analyzes student performance data by calculating the sum of successful completion rates (represented by even numbers) that occurred at key assessment checkpoints (even positions) in the historical assignment data. This calculation will help determine the optimal difficulty adjustment for future assignments based on demonstrated student success patterns.
    

    
def sum_even_and_even_index(arr):
    """
    Create a function that analyzes student performance data by calculating the sum of successful completion rates (represented by even numbers) that occurred at key assessment checkpoints (even positions) in the historical assignment data. This calculation will help determine the optimal difficulty adjustment for future assignments based on demonstrated student success patterns.
    

    """
def sum_even_and_even_index(arr):
    """
    Create a function that analyzes student performance data by calculating the sum of successful completion rates (represented by even numbers) that occurred at key assessment checkpoints (even positions) in the historical assignment data. This calculation will help determine the optimal difficulty adjustment for future assignments based on demonstrated student success patterns.
    

    """
    i = 0
    sum = 0
    for i in range(0, len(arr), 2):
        if arr[i] % 2 == 0:
            sum += arr[i]
    return sum