Answer:
Q1.)Public interest groups are similar to nonpartisan groups because a public interest group can be a nonpartisan group and be free from ties to any political parties. In ways they still differ because public interest group can still also be part of a political party.
Q2.)How do lobbyists differ from political action committees (PACs)
Q3.)Interest groups influence public policy through lobbying of their specific special interest they have in mind. The number one way interest groups affect public policy is by providing information to politicians. It is illegal for interest groups to give money to politicians.
Q3.)I don't know this one
Q4.)Interest groups are different from political parties in the sense that they are the ones paying the political parties to help them represent certain views or get certain bills passed in their favor.