A factory has three production lines producing glass sheets that are all supposed to be of the same thickness. A quality inspector takes a random sample of n = 30 sheets from each production line and measures their thicknesses. The glass sheets from the first production line have a sample average of 1 = 3.015 mm with a sample standard deviation of s1 = 0.107 mm. The glass sheets from the second production line have a sample average of 2 = 3.018 mm with a sample standard deviation of s2 = 0.155 mm. while the glass sheets from the third production line have a sample average of 3 = 2.996 mm with a sample standard deviation of s3 = 0.132 mm. What conclusions should the quality inspector draw?