What does it imply for a distribution to be symmetric?
Both the area above the mean and the area below the mean are
equal to 0.50. See solution for details.
Practice makes perfect
We know that a normal distribution is symmetric, with the mean as the axis of symmetry. This means that the half of the distribution below the mean is a mirror image of the half of the distribution above the mean. Therefore, both the area above the mean and the area below the mean are equal, and each represents 50 % of the graph's area.
