The trade magazine QSR routinely checks the drive-through service times of fast-food restaurants. An 80% confidence interval that results from examining 580 customers in Taco Bell's drive-through has a lower bound of 170.8 seconds and an upper bound of 174.6 seconds. Complete parts (a) through (c). (a) What is the mean service time from the 580 customers? The mean service time from the 580 customers is (Type an integer or a decimal. Do not round.) seconds