SCENARIO 9-3
an Appliance Manufacturer Claims to Have Developed a Compact

SCENARIO 9-3
An appliance manufacturer claims to have developed a compact microwave oven that consumes a
mean of no more than 250 W. From previous studies, it is believed that power consumption for
microwave ovens is normally distributed with a population standard deviation of 15 W. A consumer
group has decided to try to discover if the claim appears true. They take a sample of 20 microwave
ovens and find that they consume a mean of 257.3 W.
-Referring to Scenario 9-3, the appropriate hypotheses to determine if the manufacturer's claim appears reasonable are: a) $H _ { 0 } : \mu = 250$ versus $H _ { 1 } : \mu \neq 250$
b) $H _ { 0 } : \mu \geq 250$ versus $H _ { 1 } : \mu < 250$
c) $H _ { 0 } : \mu \leq 250$ versus $H _ { 1 } : \mu > 250$
d) $H _ { 0 } : \mu \geq 257.3$ versus $H _ { 1 } : \mu < 257.3$