Answer: 26.3 mm
Step-by-step explanation:
According to the two-standard deviations rule for outliers, the values that does not lie within 2 standard deviations from mean are outliers.
If Mean = 23.5 millimeters (mm) and standard deviation = 1.4 mm
Then, greatest thickness need to check = mean + 2 (standard deviation)
= 23.5 + 2(1.4)
= 23.5 + 2.8
= 26.3 mm
hence, the greatest thickness that would require the statistician to check the configuration of the machine = 26.3 mm.