To carry the Energy Star Logo, a 25 cubic-foot French-doorrefrigerator must use no more than 574 kW-h/year (ignore the weirdunits). If they use significantly more than that, they are removedfrom the list (which recently happened). A sample of 23refrrigerators o fac ertain modle is tested by an independentcompany. They are found to use an average of 596 kW-h/year, with asample standard deviation of 18.7 kW-h/year.
a) Write the hypotheses being tested.
b) Give a p-value range for this claim. is it significant at thea=.05 level, using that level what do you conclude?
c) Before the government makes a final decision, they will dotheir own study of the same model, but we want to get the margin oferror down to 10 kW-h/year. How many refrigerators should theytest, assuming a=.05 and that the standard deviation will be aboutthe same as the first study (18.7 kW-h/years)?
