A global financial institution transfers a large data file every evening from offices around the world to its London headquarters. Once the file is received, it must be cleaned and partitioned before being stored in the company's data warehouse. Each file is the same size, and the time required to transfer, clean, and partition a file is normally distributed, with a mean of 1.5 hours and s standard deviation of 15 minutes.
A) What percentage of the files will take between 80 minutes to 120 minutes to be transferred, cleaned and partitioned?