A certain oat cereal manufacturer boasts that adults who eat its cereal every day have lower cholesterol levels. To test this claim, a nurse measures the cholesterol levels of 18 patients. These patients are instructed to eat the oat cereal every day for four weeks. At the end of this four-week period, the nurse measures the cholesterol levels again. The differences in cholesterol levels open paren before minus after close paren are listed. A negative difference means that a patient’s cholesterol level increased over the four weeks. negative 18 comma 5 comma 9 comma negative 1 comma 0 comma 4 comma 3 comma negative 2 comma 0 comma 11 comma 5 comma 12 comma negative 5 comma 1 comma negative 3 comma 4 comma 8 comma 9 Assuming the conditions for inference are met, what is the test statistic for testing the hypotheses ratio of cap h sub 0 to mu sub diff is equal to 0 ; ratio of cap h sub A to mu sub diff is greater than 0 ?