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.
-True or False: Referring to Scenario 9-3, the consumer group can conclude that there is enough
evidence that the manufacturer's claim is not true when allowing for a 5% probability of
committing a Type I error.

Question

Quizplus · Accepted Answer

The consumer group can perform a hypothesis test with the null hypothesis that the mean power consumption is 250 W. Given the sample mean of 257.3 W, a standard deviation of 15 W, and a sample size of 20, they can calculate the test statistic and compare it to the critical value for a 5% significance level. If the test statistic exceeds the critical value, they can reject the null hypothesis, suggesting there is enough evidence to doubt the manufacturer's claim.

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