I’m studying for my Excel class and don’t understand how to answer this. Can you help me study?

Hello, This assignment is related to Engineering economics. There are four questions.

Both questions three and four have a parts needed to be fully completed.

And there is a bonus question at the end for extra point I need it to be done.

Please read the written below carefully

You should submit your answers as a single PDF file. For Problem #1, please paste in any Excel tables that you use to produce your answers into your document so that they are in the single PDF file.

I will be uploading a file which includes everything on it, please read all the written instructions and the problems carefully.