This is a popup of a normal distribution graph, showing students the probable spread of data within 1, 2, 3, and 4 standard deviations of the mean. The formulas for the population standard deviation and the sample standard deviation are both included. It is a great reference/graphic organizer for student notebooks and I have even had students who weren't in my class ask to join because they wanted this popup too. Useful for math or maths class, great for visual and kinesthetic learners, and