Calculation of the problems and Interpretation of results:

1) For calculation of exercise # 1 see earlier slide. The result of exercise # 1 is 15.9%. This means that 15.9% of normal healthy individuals have a heart rate above one standard deviation (greater than 80 beats per minute).

2) Calculation for exercise #2

Z = X- μ z = 90-70 = 20/10 = 2.00. If we look at the normal distribution tables, then the z value of 2.00 corresponds to 0.023 or 2.3%

σ 10

This means that 2.3% of normal healthy individuals have a heart rate above two standard deviation (greater than 90 beats per minute).

3) Calculation for exercise # 3

Z = X- μ Z1 = 50-70 = -20/10 = -2.00 and Z2= 90-70/10 =2.00. The area between -2 standard deviations and +2 standard deviations from

σ 10

The z tables is 0.954 or 95.4%.

This means that 95.4% have a heart rate between -2 and +2 standard deviations (between 50 -90 beats per minute).