If scores on the Wechsler Adult Intelligence Scale (WAIS) are normally distributed, with a mean of 100 and a standard deviation of 15, what percentage of scores will fall between 85 and 115?

Renee hiked for 6 3/4 miles. after resting, renee hiked back along the same route for 5 1/4 miles. how many more miles does renee need to hike to return to the place where she started? represent your answer as a simplified mixed number, if necessary.