Answer:The hazardous waste disposal cost per unit  for chair and table respectively is $2.83 and $1.54
Explanation:
From the question, If cost are assigned at a rate based on direct labor hours, then the  total disposal cost for chairs is
total disposal cost for chairs =Direct labor hours required for chairs/Total Direct labor hours required for both furniture x Hazardous waste disposal costs
 268,000/ 268,000+16,400  x 615,000
 = 268,000/ 284,400  x  615,000
===$595,535.865
 and for tables for  is
total disposal cost for tables=Direct labor hours required for tables /Total Direct labor hours required for both furniture x Hazardous waste disposal costs
16,400 / 268,000+16,400  x  615,000
 = 16,400 / 284,400  x 615,000
===$35,464.135
The hazardous waste disposal cost per unit  for chair and table respectively is
For chair ====total disposal cost for chairs/ Expected production of chairs
$595,535.865/210,000 units= $2.83
For table ====total disposal cost for table/ Expected production oftable
$35,464.135/23,000 units=$1.54