Mumford Corporation invested $30.000 in marketable securities at various times during the year. On December 9 , it sold some of these investments for $10,000, and on December 18 , it sold more of these investments for $5,000. The securities sold on December 9 had cost the company $7,000, whereas the securities sold on December 18 had cost the company $6,000. a. Record the purchase of marketable securities during the year. b. Record the sale of marketable securities on December 9. c. Record the sale of marketable securities on December 18. d. Record the necessary fair value adjustment on December 31, assuming that the market value of the company's remaining unsold securities was $20,000. Complete this question by entering your answers in the table below. Record the sale of marketable securities on December 9. (if no entry is required for a transaction/event, select "No journa required" in the first account field.) Journal entry worksheet Record the sale of marketable securities on December 9. Note: Enter debits before credits