At a large business, employees must report to work at 7: 30 a. m. the arrival times of employees forms approximately a bell-curve distribution with mean 7: 22 a. m. and standard deviation 4 minutes. (a) use the 68-95-99.7 rule (also known as the empirical rule) to determine what percent of employees are late on a typical day. % (b) a psychological study determined that the typical worker needs four minutes to adjust to their surroundings before beginning their duties. use the 68-95-99.7 rule (also known as the empirical rule) to determine what percent of this business' employees arrive early enough to make this adjustment before the 7: 30 a. m. start time. %