A dairy produces milk with an average of 18.24 grams of fat in each quart. The dairy supervisor hypothesizes that skinny cows will produce milk with less fat. After 26 quarts of milk are randomly selected from 26 different skinny cows, the fat content is measured with a resulting average of 17.98 grams per quart and a standard deviation of 1.16 grams per quart. At the a = .01 significance level, test the supervisor's hypothesis.