Divisibility by 11 uses the alternating sum of digits (odd-position digits minus even-position digits, counted from the right).

For 978626: digits from the right are 6,2,6,8,7,9. Odd positions sum to \(6+6+7=19\); even positions sum to \(2+8+9=19\).

Since the difference \(19-19=0\) is divisible by 11, the number itself is divisible by 11.

The other three numbers give a non-zero alternating-sum difference when checked the same way.

Hence, 978626 is divisible by 11.