do the first 4 questions and show work

C-2 The business owner gets its product tested by a vendor. The unit cost for testing is twice as much for each of the first 400 units per month as compared to each unit above 400 . The vendor charged $31,500 this month for 500 units. Find A. Average cost per unit. B Cost per unit below the price break point. C. Marginal cost for the 650th unit C-3 A person invested $6000 in stock the market. The economy was bulling and return was 9% on average for first 6 years. Then there was a downturn and return was average of 6% for the next 4 years. How much is in the account after 10 years? What is the average return over 10 years? ( 2 decimal) C-4 The initial cost of smog control is $10,000 and after 10 years of useful life it needs to be discarded with as hazardous substance with a dismantling cost of $2000. The maintenance costs are as below;- The smog control board is providing the financial support for everything (cost +10 yrs of maintenance) How much should they pay to the firm now? Interest rate 6%