"2. why did some people want representation to be based on population? "

Answer and Explanation:

Some people wanted representation to be based on population—they wanted proportional representation—because it would favor their states which were larger than other states in terms of population: they knew that they would have more power in government if representation in congress was done in proportion to each state's population; and so they reasoned that the states that had the largest populations, should be represented by more seats or candidates.