The trade magazine QSR routinely checks the drive-through service times of fast-food restaurants. A 99% confidence interval that results from examining 641 customers in Taco Bell's drive-through has a lower bound of 158.5 seconds and an upper bound of 162.7 seconds. Complete parts (a) through (c). . . . .. (a) What is the mean service time from the 641 customers? The mean service time from the 641 customers is seconds (Type an integer or a decimal. Do not round.)