Final answer:
Each state's representation in the Senate is determined by equal representation, meaning every state has two senators regardless of population. The senators are elected by popular vote.
Step-by-step explanation:
The representation of each state in the Senate is determined by equal representation, meaning that each state has two senators regardless of population. This ensures that each state is represented equally and that the interests of both large and small states are considered. The senators are elected by popular vote since the ratification of the Seventeenth Amendment in 1913.