1. The problem statement, all variables and given/known data According to Nielsen Media Research, kids ages 12-17 watch an average of 3 hours of tv per day. Suppose that the standard deviation is 1 hour and that the distribution of time spent watching tv has a bell-shaped distribution. a) what percentage of kids aged 12-17 watch tv between 2 and 3 hours per day? 2. Relevant equations 1-1/z^2 3. The attempt at a solution The standard deviation of 2 hours is 1, from the mean. But the value of z has to be greater than 1. With a question that has a range in it, usually means both sides will have a standard deviation from the mean. But one side is 1 and the other is the same as the mean. So we only have one side, and I divided 1 in half to get .5 and plugged it into the formula. 1-1/.5^2 1-1/.25 1-4 -3 The answer is 34%. I know I'm missing a step but I don't know what step. The formula is pretty straight forward and I get it, but this problem is really messing me up.