Answer:
more than 15.40 cm and less than 14.60 cm
Step-by-step explanation:
A manufacturer of bolts has a quality control policy that requires it destroy any bolts that are more than 4 standard deviations from the mean.
mean length= 15 cm
standard deviation= 0.10 cm
4 standard deviation from mean= 15±(4×0.10)
therefore, bolts of length more than 15+0.4, and less than 15-0.4 will be destroyed
= 15.40 cm and 14.60 cm
The answer is A. 9, 12, 15,
