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

Question

Quizplus · Accepted Answer

Given the sample size, mean, population standard deviation, and significance level, a statistical test (such as a one-sample z-test) can be conducted to determine if the observed mean significantly differs from the claimed mean. If the test statistic falls into the critical region (which corresponds to a 5% probability of committing a Type I error), it would indicate that there is enough evidence to reject the manufacturer's claim.

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