For patients who have been given a diabetes test, blood-glucose readings are approximately normally distributed with mean 127 mg/dl and a standard deviation 8 mg/dl. Suppose that a sample of 4 patients will be selected and the sample mean blood-glucose level will be computed. According to the empirical rule, in 95 percent of samples the SAMPLE MEAN blood-glucose level will be between the lower-bound of and the upper-bound of