The times per workout an athlete uses a stair climber are

Last updated: 8/8/2022

The times per workout an athlete uses a stair climber are normally distributed with a mean of 20 minutes and a standard deviation of 5 minutes. What percentage of athletes use the stair climber for less than 18 minutes? (A) 20.33% (B) 34.46% (C) 48.41% (D) 65.54%