A biology researcher is studying the risk of extinction of a rare tree species in a remote part of the Amazon. In the course of her study, the researcher models the trees' ages using a normal distribution with a mean of 255 years and a standard deviation of 50 years. Use this table or the ALEKS calculator to find the percentage of trees with an age between 221 years and 317 years according to the model. For your intermediate computations, use four or more decimal places. Give your final answer to two decimal places (for example 98.23%). %