Reduced heart rate variability (HRV) is known to be a predictor of mortality after a heart attack. One measure of HRV is the average normal-to-normal beat interval (in milliseconds) for a 24-hr time period. Twenty-two heart attack patients who were d owners and 80 heart attack patients who did not own a dog participated in a study of the effect of pet ownership on HRV, resulting in the summary statistics shown in the accompanying table. Measure of HRV (Average Normal-to-Normal Beat Interval) Mean Standard Deviation Owns Dog 878 138 Does Not Own Dog 800 133 (a) The authors of this paper used a two-sample t test to test H:41-42 = 0 versus H: 41-42 +0. What conditions must be met in order for this to be an appropriate method of analysis? (Select all that apply.) The samples must be paired. The samples must be randomly selected from or representative of their populations of interest. The population distributions must be approximately normal. Both sample sizes must be at least 30. Both sample sizes must be at least 30 or the population distributions must be approximately normal. The samples must be independently selected. None of the above (b) The paper indicates that the null hypothesis in part (a) was rejected and reported that the P-value was less than 0.05. Carry out a two-sample t test. (Use a = 0.05. Use 4, for heart attack patients who are dog owners and un for heart attack patients who do not own a dog.) Find the test statistic and P-value. (Use technology. Round your test statistic to one decimal place and your P-value to three decimal places.) t = 2.4 P-value = .029 State the conclusion in the problem context. Is your conclusion consistent with the one given in the paper?