How do I break-down this problem to find the best possible answer? What is the 68-95-99.7 rule?
The systolic blood pressure of a group of 18-year-old women is normally distributed with a mean of 120 mmHg and a standard deviation of 12 mmHg. What percent of 18-year-old women in this group have a systolic blood pressure between 108 mmHg and 132 mmHg?