4. Calculate the delay x data rate product for the following links. Use only one-way measured the first bit sent by the send to the first bit received by the destination. (a) A link with a data rate of 100 Mbps (Megabits per second) with a one-way delay of 10 microseconds. (b) A link with a data rate of 1.5 Mbps (Megabits per second) and one-way delay of 50 microseconds. (c) A satellite link with a data rate of 1.5 Megabits per second and 40,000 Kilo meters above the earth. The only delay is the propagation delay and signals travels with the speed of light ( \( 3 \times 10^{8} \) meters per second).