stats and prob

The annual rainfall in a certain region is modeled using the normal distribution shown below. The mean of the distribution is 30.8 cm and the standard deviation is 3.3 cm. In the figure, there are three missing values to fill in along the axis. The middle value is under the highest part of the curve. And, the left and right values are each the same distance away from the middle value. Use the empirical rule to choose the best value for the percentage of the area under the curve that is shaded, and fill in the missing values along the axis. Percentage of total area shaded: (Choose one) X 5 ? 20 25 30 1 35 40 Rainfall (in cm )