the train and roller coaster will arrive back at their stations at the same time. if the train had a .15 mile head start and is traveling at the speed of .65 miles per minute, and the roller coaster is traveling at an average speed of .78 miles per minute, how long before they both arrive at the station?

The ages of personnel in the accounting department of a large company are normally distributed with a standard deviation of 7 years. there is a 0.02275 probability that the age of any randomly chosen person in the department is less than 22 and 0.15866 probabilty that the age of any randomly chosen person is greater than 43. what is the mean of this distribution?