In a study of facial behavior, people in a control group are timed for eye contact in a 5-minute period. Their times are normally distributed with a mean of 184.0 seconds and a standard deviation of 55.0 seconds (based on data from "Ethological Study of Facial Behavior in Non-paranoid and Paranoid Schizophrenic Patients," by Pittman, Oik, Orr, and Singh, Psychiatry, Vol. 144, No. 1). Use the 68-95-99.7 rule to find the indicated quantity.
a. Find the percentage of times within 55.0 seconds of the mean of 184.0 seconds.
b. Find the percentage of times within 110.0 seconds of the mean of 184.0 seconds.
c. Find the percentage of times within 165.0 seconds of the mean of 184.0 seconds.
d. Find the percentage of times between 184.0 seconds and 294 seconds.