Earth Sciences homework help

I am having trouble solving this problem in excel. I am not sure what I am supposed to do and with which forumulas. https://gyazo.com/764eb1edece145737900b924ebb4b7achttps://gyazo.com/5b81977478b0cbbfbed97a20c4302e47The excel file is attached as well as screen shots of the glade manual.