The average weight of a 12 year old boy in the United States is 96 lb. In a sample of 36 twelve-year-old boys at a given doctor's office, the average weight was 87 pounds (standard deviation is 16). Is the average weight of the boys at the doctor's office significantly lower than the national average? Calculate the z or t test statistic and write the value in the box below. Round to the nearest hundredths place. Your