In order for a kitchen appliance to be considered “green” it should draw less than 250…

In order for a kitchen appliance to be considered “green” it
should draw less than 250 watts. An appliance manufacturer claims
to have developed a new “green” toaster oven that consumes an
average of no more than 250 W. From previous studies, it is
believed that power consumption for toaster ovens is normally
distributed with a standard deviation of 18 W. A consumer group
suspects the actual average is more than 250 W. They take a sample
of 20 toaster ovens and calculate the average consumption to be 260
W. Design and run a test with α = .06 to see if the consumer groups
suspicions are justified.
Calculate the probability of a type two error, for the test
above If the actual mean power usage of the new oven is 251
watts.