When Xochitl runs the 400 meter dash, her finishing times

Last updated: 7/20/2022

When Xochitl runs the 400 meter dash, her finishing times are normally distributed with a mean of 84 seconds and a standard deviation of 2.5 seconds. Using the empirical rule, determine the interval of times that represents the middle 68% of her finishing times in the 400 meter race.