Answer
The answer and procedures of the exercise are attached in the following archives.
Explanation
You will find the procedures, formulas or necessary explanations in the archive attached below. If you have any question ask and I will aclare your doubts kindly.
Answer:
(a)
For Job G15:
Direct labor = $20,000
Overhead applied = 16,000
Overhead rate = 
= 0.8 × 100
= 80%
Overhead applied = Direct labor × 80%
= $20,000 × 80%
= $16,000
Overhead is applied on direct labor. Hence, rate is 80%.
Overhead for Job B10 = Direct labor × 80%
= $54,000 × 80%
= $43,200
Therefore,
Total overhead applied = $43,200 + 45,750 + 16,000
= $104,950
(b) Hence,
Overapplied overhead for February:
= Total overhead applied - Actual Overhead
= $104,950 - $68,500
= $36,450
The item that has many close substitutes tend to have an elastic demand since this means that the consumers have a lot of variations to choose from. This makes the demand for the item very dependent on the number of consumers this item caters. The more substitutes mean more competition, more choices for the consumers, less demand for a particular item.
