Answer and Explanation:
The computation is shown below;
a. On book value basis
Particulars    Book value   Weight
Debt          $70        0.2373
            (7 × $10)
common stock  $225       0.7627
         ($120 + $105)
Total           $295
b. On market value basis
Particulars    Market value   Weight
Debt          $553        0.7158
     (7 × $79)
common stock  $219.60      0.2842
      (120 × 0.92 + 105 × 1.04)
Total           $772.60
c. The market value weight is more relevant