Downloaded from https://www.everyspec.com A certain fusJe Is experiencing reliability pro~lemn. Bt is redesigned and both fuse designo are tested to determine if the new deisigns have s-significartly better re- liability. The fuses of original design have an estimated mean life of 80,000 hr with an estiraiated standard deviation of 500 hr (100 fuses tested), and the redesigned faxse have an estimated mean life of 31, 000 hr with an estimated standard deviation of 560 hr (100 fuses tested). Does the redesigned fuse have better reliability at the 90% level of a-confidenoe. IA. &&totthe parameters of the LA. 2A 311000, ?.30,000 problem.
Assume that the standard deviation estimat A* o) ~ 0 wrau the v-statistic. The units of hours wfill be implied for NA 100, NS 100- 1B, Malte the explict assumption of a-normality for both fuse de- signs..J iC. Be explicit about the measure 10. The measure of reliability wilt be the of reliability, true moam-life of th'o fuse. ID. Assume qA sm on. 2. Compute the degrees of free- 2. P 100 + 100 -2 -198. dom from Table 2-44 ~'NA +NS - 2, 8. Cow ute a, from Tzble 2-24 S.3 (100 - j)(16213 + (100 - 1)(Bo0) 100 +100... 4,. (& 11A L*k - 531. NA +pin5i2 4. Determine the critical value of 4. For Y - 198 andl 1-sided 00% s-confidence, 0 for lesWhed 90% a-confidence, t 1.26. from Table 2-27. 8.
Compute 5/ . V 128(581)(00~ +j )0 o m + j~'-, an uncer- . tainy in the dtfftoreno of the means.