Final answer:
If western Pennsylvania and eastern Ohio wanted to form a new state, the approval would need to come from both the state legislatures of Pennsylvania and Ohio, as well as the U.S. Congress.
Step-by-step explanation:
If western Pennsylvania and eastern Ohio wanted to form a new state, the approval would need to come from several parties. According to the Constitution, for a new state to be formed, it requires the approval of the state legislatures of both Pennsylvania and Ohio, as well as the approval of the U.S. Congress. The process would involve both states passing legislation to approve the formation of the new state and then submitting a petition to Congress for consideration. Congress would then need to vote and approve the formation of the new state.