6. In a study of heart surgery, one issue was the effect of drugs called beta-blockers on the pulse rate of patients during surgery. The available subjects were divided at random into two groups of 30 patients each. The treatment group received a beta-blocker, while the control group received a placebo (fake treatment). The pulse rate of each patient at a critical point during the operation was recorded. The treatment group had a mean pulse rate of x1 = 65.2 beats per minute with a standard deviation of s, = 7.8 beats per minute. The control group had a mean pulse rate of x2 = 70.3 beats per minute with a standard deviation of s, = 8.3 beats per minute. Do the data above provide sufficient evidence that patients who receive beta-blockers during surgery tend to have a lower mean pulse rate than patients who receive a placebo during surgery? (20 pts) (a) State your null and alternative hypotheses. (Fill in the space with "=', ">", or "