Exercise 6 Randomly selected students participated in an experiment to test their ability to determine when 1 minute has passed. Forty students yielded a sample mean of 53.3 seconds {assume 0' = 9.5}. Based a 95% condence interval, is it likely to have an overall mean of 1 minute? Exercise 7 When 14 different second-year medical students measured the blood pressure of the same person, they obtained the results listed below. Assuming the true standard deviation is known to be 1|] mmHg, construct a 90% condence interval of the true mean blood pressure for the patient. SAMPLE: 133, 130, 135, 140, 120, 125, 120, 130, 130, 144, 143, 140, 130, 150 Exercise 8 What sample size is needed to estimate the mean white blood cell count (in cells per microliter} for the population of adults in the United States? Assume you want a 99% condence interval that the sample mean is within i2 cellspr of the true mean. The population standard deviation is given as 2.5 cellsfuL