Final answer:
When two QAM channels, each with a throughput of 38 Mbps, are bonded, the downstream throughput becomes 76 Mbps by adding the throughputs together.
Step-by-step explanation:
The subject of this question falls under the category of Physics, specifically within the realm of Computers and Technology as it deals with understanding data transmission rates using Quadrature Amplitude Modulation (QAM) and the concept of channel bonding. Channel bonding is a technique used in telecommunications where two or more channels are combined to increase the throughput.
To find the downstream throughput when two QAM channels with a throughput of 38 Mbps each are bonded, you perform a simple arithmetic calculation. You add the throughput of the first channel to the throughput of the second channel, which in this case are both 38 Mbps:
38 Mbps (Channel 1) + 38 Mbps (Channel 2) = 76 Mbps
Therefore, the combined downstream throughput after bonding the two channels would be 76 Mbps.