TABLE 9-2 An Appliance Manufacturer Claims to Have Developed a Compact Microwave

Short Answer

TABLE 9-2
An appliance manufacturer claims to have developed a compact microwave oven that consumes a population 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. If there is evidence that the population mean consumption is greater than 250 W, the manufacturer will be unable to make the claim.
-Referring to Table 9-2, if you select a sample of 20 compact microwave ovens and are willing to have a level of significance of 0.05, the probability of making a Type II error is ________ if the mean power consumption of all such microwave ovens is in fact 257.3 W.