Answer:
The standard deviation is above 6 mm, which means that this batch does not pass the technical control.
Step-by-step explanation:
Mean of the batch:
The mean of the batch is the sum of all values divided by the number of items. So
Mean in the desired interval.
Standard deviation:
Square root of the sum of the difference squared between each term and the mean, divided by the number of itens. So
The standard deviation is above 6 mm, which means that this batch does not pass the technical control.