65. Fifteen air samples from a certain region were obtained, and for each one the carbon monoxide concentrationwas determined.The results (in ppm) were 9.3 10.7 8.5 9.6 12.2 15.6 9.2 10.5 9.0 13.2 11.0 8.8 13.7 12.1 9.8 Using the interpolation method suggested in Section 1.3, compute the 10% trimmed mean.