SCENARIO 10-12
a Quality Control Engineer Is in Charge of the Manufacture

SCENARIO 10-12
A quality control engineer is in charge of the manufacture of USB flash drives. Two different
processes can be used to manufacture the flash drives. He suspects that the Kohler method produces a
greater proportion of defects than the Russell method. He samples 150 of the Kohler and 200 of the
Russell flash drives and finds that 27 and 18 of them, respectively, are defective. If Kohler is
designated as "Group 1" and Russell is designated as "Group 2," perform the appropriate test at a
level of significance of 0.01.
-Referring to Scenario 10-12, the hypotheses that should be tested are: a) $H _ { 0 } : \pi _ { 1 } - \pi _ { 2 } = 0$ versus $H _ { 1 } : \pi _ { 1 } - \pi _ { 2 } \neq 0$
b) $H _ { 0 } : \pi _ { 1 } - \pi _ { 2 } \neq 0$ versus $H _ { 1 } : \pi _ { 1 } - \pi _ { 2 } = 0$
c) $H _ { 0 } : \pi _ { 1 } - \pi _ { 2 } \leq 0$ versus $H _ { 1 } : \pi _ { 1 } - \pi _ { 2 } > 0$
d) $H _ { 0 } : \pi _ { 1 } - \pi _ { 2 } \geq 0$ versus $H _ { 1 } : \pi _ { 1 } - \pi _ { 2 } < 0$