All right, now let's work this out together. They're telling us that the distribution of resting pulse rates are approximately normal. So we could use a normal distribution, and they tell us several things about this normal distribution. They tell us that the mean is 80 beats per minute, so that is the mean right over there, and they tell us that the standard deviation is nine beats per minute. So on this normal distribution, we have one standard deviation above the mean, two standard deviations above the mean, so this distance right over here is nine, so this would be 89. This one right over here would be 98, and you could also go standard deviations below the mean. This right over here would be 71.