integrated circuits. Ten wafers were tested, and the fallowits photonedet thickness meanumonts (in angations
x, 000 ) were observed: 13-3997, 13-3957, 13-3902, 13-4045, 13-4005, 13, 9912, 13, 7985, 17, 3925, 13.3946, and 13-4002.
a. Test the hypothesis that mean thickness is
13.4\times 1.900A. Use
a=0.05 asi ancere a no-sided altrmative.
b. Find a
99% two-sided confidence intercal on mean photoresist thickness. Amome that thickess is sormuly distribeted.
c. Does the sormality assumption seem reasonable for these data?