General Electric (GE), an appliance manufacturer, claims to have developed a microwave that consumes an average of no more than 300 W. From previous studies, it is believed that power consumption for microwaves is normally distributed with a standard deviation of 20 W. The quality assurance team from another competitor has decided to try to discover if the claim appears true. They take a sample of 20 microwaves and find that they consume an average of 357.4 W.

What is the population of interest.

a. The power consumption in the 20 microwaves.
b. The power consumption in all such microwaves.
c. The mean power consumption in the 20 microwaves.
d. The mean power consumption in all such microwaves.