Please help I have no idea what to do.

ll Verizon LTE 8:19 PM webwork.math.ttu.edu Results for this submission Entered Answer Preview Result 9770.64 9770.64 incorrect incorrect 6959.37 6959.37 incorrect At least one of the answers above is NOT correct. 1 of the questions remains unanswered. (1 point) Payments of $300 per quarter are made from June 7, Z through December 7,Z+ 11, inclusive. If the nominal rate of interest convertible quarterly is 6%; a) Find the present value on September 7, Z-4. ANSWER $ 9770.64 b) Find the current value on March 7, Z+9. ANSWER $ c) Find the accumulated value on June 7. Z+ 12. ANSWER $ 6959.37 Note: You can earn partial credit on this