Answer:
Labour rate variance  =   $260 favourable
Explanation:
The rate variance would be the difference between the standard labour cost of the 2,300 units sold and the actual labour cost
Standard labour cost  (3600/1200× 2300)    6,900
Actual labour cost                       6, 640
labour rate variance                    $260 favourable
The variance is favourable because the StuckinMyHouse book company saved $260 as a result of of his actual cost been less than the expected cost.