10. (6 points) Among five numbers, the sum of the average of any four numbers plus the remaining one number is $74$, $80$, $98$, $116$, $128$, respectively. The smallest number among the five numbers is smaller than the largest number by $\qquad$.

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Note: The blank at the end is left as in the original text, indicating a space for the answer.
【Solution】Solve: $(128 \times 4-74 \times 4 ） \div 3$
$$
\begin{array}{l}
=(512-296) \div 3 \\
=216 \div 3 \\
=72 ;
\end{array}
$$

Answer: The smallest number among the five numbers is 72 less than the largest number.
Therefore, the answer is: 72.