Acertain pen has been designed so that true mean writing lifetime under controlled conditions (involving the use of a writing machine) is at least 10 hours. a random sample of 18 pens is selected, the writing lifetime of each is determined, and a normal quantile plot of the resulting data supports the use of a one-sample t test. (a) what hypotheses should be tested if the investigators believe a priori that the design specification has been satisfied? (b) what conclusion is appropriate if the hypotheses of part (a) are tested, t = - 2.3, and α = .05? (c) what conclusion is appropriate if the hypotheses of part (a) are tested, t = - 1.8, and α = .01? (d) what should be concluded if the hypotheses of part (a) are tested and t = - 3.6?