The article “Calibration of an FTIR Spectrometer” (P. Pankratz, Statistical Case Studies for Industrial and Process Improvement, SIAM-ASA, 1997:19–38) describes the use of a spectrometer to make five...

The article “Calibration of an FTIR Spectrometer” (P. Pankratz, Statistical Case Studies for Industrial

and Process Improvement, SIAM-ASA, 1997:19–38) describes the use of a spectrometer to make five measurements of the carbon content (in ppm) of a certain silicon wafer on each of two successive days. The results were as follows:

Can you conclude that the calibration of the spectrometer has changed from the first day to the second day?