
    Design a function that analyzes a sequence of student performance scores to calculate the total number of successful completions (represented by even scores) achieved during key assessment checkpoints (even-positioned scores) in the adaptive learning pathway. The function should only consider scores that are both even-numbered and occur at even positions in the sequence, as these represent successfully completed checkpoints that will influence the system's difficulty adjustment.
    

    
def sum_even_and_even_index(arr):
    """
    Design a function that analyzes a sequence of student performance scores to calculate the total number of successful completions (represented by even scores) achieved during key assessment checkpoints (even-positioned scores) in the adaptive learning pathway. The function should only consider scores that are both even-numbered and occur at even positions in the sequence, as these represent successfully completed checkpoints that will influence the system's difficulty adjustment.
    

    """
def sum_even_and_even_index(arr):
    """
    Design a function that analyzes a sequence of student performance scores to calculate the total number of successful completions (represented by even scores) achieved during key assessment checkpoints (even-positioned scores) in the adaptive learning pathway. The function should only consider scores that are both even-numbered and occur at even positions in the sequence, as these represent successfully completed checkpoints that will influence the system's difficulty adjustment.
    

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