8. Solution. The greatest deviation from the average among the measurements that have been preserved is 37 g, which does not exceed $10 \%$ of the nominal mass of the portion. The deviations of the measurements that cannot be read are less than 37 g: for example, the number 41 ? is less than 420, so the deviation of the number 41 ? from the average is less than 19. Therefore, all deviations are no more than 37 g.

The standard deviation does not exceed the greatest deviation, so the standard deviation is no more than 37 g. The machine does not require repair.
Answer: not required.

## Evaluation Criteria

The solution is complete and correct. Other reasoning is possible. For example, the participant added the missing values in such a way as to not reduce the standard deviation, found the standard deviation of the resulting set, and indicated that the deviation of this set is no greater.

The answer is correct, but there is an assessment of the root mean square deviation from the nominal mass of 400 g, not the standard deviation. Further reasoning is correct.

The solution is incorrect or absent.

3 points

1 point 0 points