A nurse at a local hospital wonders if the firstborn twin is taller than the second-born. He randomly selects the medical records of 33 sets of twins and finds the differences open paren firstborn minus second-born close paren in the twins’ heights, in centimeters. The mean of the differences is 1 point 1 centimeters with a standard deviation of 2 point 3 centimeters. Assuming that 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 ?