1. The problem statement, all variables and given/known data It has been projected that the average and standard deviation of the amount of time spent online using the Internet are, respectively, 14 and 17 hours per person per year (approximately normally distributed). What value is exactly 1 standard deviation below the mean? 2. Relevant equations Emiprical Rule [tex]\mu \pm \sigma[/tex] contains approximately 68% of the measurements. [tex]\mu \pm 2\sigma[/tex] contains approximately 95% of the measurements. [tex]\mu \pm 3\sigma[/tex] contains approximately almost all of the measurements. 3. The attempt at a solution In similar problems, the mean is the larger number in the problem, so solving the problem is a simple matter of subtracting the standard deviation from the mean to find out the percentage of population. In this case though, the standard deviation (17) is greater than the mean(14)? If I solve this like I do normal problems, this would leave me with a negative value for time spent on the Internet. Is this an error in the text book or is there something I'm missing here?