Suppose each user requires 500 kbps and is active only for 25% of the time. How many users can we multiplex on a 8 Mbps link if we want to fulfill user requirements with probability at least 0.9 using...

Suppose each user requires 500 kbps and is active only for 25% of the time. How many users can we multiplex on a 8 Mbps link if we want to fulfill user requirements with probability at least 0.9 using packet switching? What is the statistical multiplexing gain in this case?