I’m thinking all of the above i’m not sure

Arival company manufactures fuel tanks for cars using a different production technique. the total weekly cost (in dollars) of producing x tanks is given by c(x) = 10000 +90x - 0.04x2 find the marginal cost at a production level of 500 fuel tanks per week to approximate the cost of the 501st unit (round to the nearest 2 decimal places, if needed)

Which are the best examples of costs that should be considered when creating a project budget?

Jamie is saving for a trip to europe. she has an existing savings account that earns 3 percent annual interest and has a current balance of $4,200. jamie doesn’t want to use her current savings for vacation, so she decides to borrow the $1,600 she needs for travel expenses. she will repay the loan in exactly one year. the annual interest rate is 6 percent. a. if jamie were to withdraw the $1,600 from her savings account to finance the trip, how much interest would she forgo? .b. if jamie borrows the $1,600 how much will she pay in interest? c. how much does the trip cost her if she borrows rather than dip into her savings?