Analysis: the sum of n numbers is, and if there is no omission, the average is. Changing the average into the number of components has little effect on the whole. If the average output is 35+, it is estimated that n is around 70. Considering that the denominator is 7, that is, n- 1 should be a multiple of 7, the estimated intervals are 7 1 and 78.

Answer: solution: from the meaning of the question, the average output is 35+, then the estimated n is about 70, so 70≤n- 1≤79.

The denominator of 35 and 5/7 is 7, that is, n- 1 should be a multiple of 7, so n is 7 1 or 78.

When n=7 1, the sum is 2556 and the divisor is 70, so it is easy to see that 56 is missing.

When n=78, the sum is 308 1 and the divisor is 77. If the divisor is divided by a factor of 7 and there is a factor of 1 1, then the molecule must be a multiple of 1 1 = 250.