Biofeedback monitoring devices and techniques in the control of physiologic functions help astronauts control stress. One experiment related to this topic is discussed by G. Rotondo, et al., Acta Astronautica, 1983. Six subjects were placed in a stressful situation (using video games), followed by a period of biofeedback and adaptation. Another group of six subjects was placed under the same stress and then simply told to relax. The first group had an average heart rate of 70.4 and a standard deviation of 15.3. The second group had an average heart rate of 74.9 and a standard deviation of 16.0. At the 10% significance level, can we say that the average heart rate with biofeedback is lower than that without biofeedback? What assumptions are necessary for your answer to be valid?