A quality control lab has just purchased a new analytical instrument to replace the old one that has served for more than 10 years. Daily operation of the old instrument include running a sample of the same batch for 10 years as quality assurance measure. The old method yielded over all these years an average value of 10.5 ppm with a standard deviation of 0.2 ppm. The new instrument has been tested for a week and the first results are shown below: 10.0 ppm 10.4 ppm 10.2 ppm 10.8 ppm 10.1 ppm 10.5 ppm 10.1 ppm Using the new instrument on the first day the technicians got a value of 9.0 ppm. Are the technicians right to exclude the measurement of the first day as an outlier at the 90% confidence level? Qexp = 0.456, Qcrit = 0.484 Qcrit,reject data point with 90 % confidence. Qexp = 0.56, Qcrit = 0.607 Qexp Qcrit, reject data point with 90 % confidence