Question

A rivet is to be inserted into a hole. A random sample of n = 15 parts is selected, and the hole diameter is measured. The sample standard deviation of the hole diameter measurements is s = 0.004 millimeters.

(a) Construct a 99% two-bounds confidence interval for σ . (b) Construct a 99% lower confidence bound for σ

Answer 1

nz15, S=0.004 a fol 99% two - bounds confidence internal foros clitical valuus are: x - x , d = 1 31.319 the ***1,1- 15-1,0.0) 2 x² 1S-1, 1-0.01 4.075 2 for es os 99% two - bounds two - brude confibeare estesual (15-1) (0.004)² 310319 (14) 3² (n-1) 5² (151)(0.004)² X 4.075 (0.00267, 0.00 +41 0000267 ² L < 0.00741 b qq% louce bound for ls confidence where, that, a = 1 154 (my) 5² ST 5-1, 0.01 29.141 V x² nt,& (15-1) (0.004)" ST 290141 Oo 00 277 Lr 8 Lower confidence bound for e 0000277 &