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 parameter of interest is
A)the mean power consumption of the 20 microwave ovens.
B)the mean power consumption of all such microwave ovens.
C)250
D)257.3

Question

Quizplus · Accepted Answer

The parameter of interest is the mean power consumption of all such microwave ovens, which is unknown. The manufacturer claims that this mean is no more than 250 W. The sample mean of 257.3 W suggests that the claim may not be true, but we cannot conclude anything without performing a hypothesis test and calculating a p-value. Therefore, the best choice is B, as we are interested in the mean power consumption of all microwave ovens, not just the 20 sampled ones.

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