In detail
1 C

2 B

3 C a = (Σy ÷ n) − [(bΣx) ÷ n] = (330 ÷ 11) − [(0.69171 × 440) ÷ 11]
= (30 −27.6684)
= 2.3316 (2.33 to 2 decimal places)

4 C {[ 2 × 20 × (4 ×20,000) ] ÷ [0.06 ×25]}0.5 = 1,461 units

5 A     Actual cost                                    $108,875
          Absorbed cost (30,000 × 3.50)       $105,000
          Under absorption                           $ 3,875