- 1. (Comparing 2 means - Ch 7.3 13 points) The heart rates (beats per minute) of a group of patients suffering from hypertension were compared to the heart rates of a control group consisting of healthy subjects: Sample mean (x) Control group 70.3 Sample standard deviation (s) 8.0 Sample size (n) 18 Hypertension group 73.1 10.0 25 a) [8] Test at a = 0.05 whether there is evidence of a difference in the mean heart rate for the two groups. In the "5-step plan", you can skip step 3 (assumptions) as this is covered in question 2 below. You can use the t-table or R to get your p-value. b) [5] Estimate the average difference in heart rate between the two groups (hypertension minus control) using a 95% confidence interval.