10.27 The widths of contact windows in certain CMOS circuit chips have a design specification of 3.5

(see Phadke et al., The Bell System Technical Journal, 1983, for details.) Postetch window widths of test specimens were as follows:

3.21, 2.49, 2.94, 4.38, 4.02, 3.82, 3.30, 2.85, 3.34, 3.91 Can we reject the hypothesis that the design specification is being met, at the 5% significance level? What assumptions are necessary for this test to be valid?