Answer:
Ivanhoe Windows
a. Journal Entries:
September 1, 2020:
Debit Cash $1,920
Credit Sales Revenue $1,920
To record the sale of windows to Geraths.
Debit Cost of goods sold $1,120
Credit Inventory $1,120
To record the cost of goods sold.
October 15, 2020:
Debit Cash $450
Credit Installation Revenue $450
To record the completion of installation service.
b. Journal Entries:
September 1, 2020:
Debit Cash $1,920
Credit Sales Revenue $1,896
Credit Unearned Revenue $24
To record the sale of windows to Geraths.
Debit Cost of goods sold $1,120
Credit Inventory $1,120
To record the cost of goods sold.
October 15, 2020:
Debit Cash $450
Debit Unearned Revenue $24
Credit Installation Revenue $474
To record the completion of installation service.
c. If Geraths is unable to develop a reliable estimate for the fair value of the installation:
Journal Entries:
September 1, 2020:
Debit Cash $1,920
Credit Sales Revenue $1,920
To record the sale of windows to Geraths.
Debit Cost of goods sold $1,120
Credit Inventory $1,120
To record the cost of goods sold.
October 15, 2020:
Debit Cash $450
Credit Sales Revenue $450
To record the completion of installation.
Explanation:
a) Data and Calculations:
July 1, 2020, Contract Price = $2,370
Standalone selling price of window = $1,920
Cost of the window = $1,120
Standalone selling price of installation service = $590
Attributed selling price of installation service = $450 ($590 = $140)
b) Estimated standalone value of the installation = estimated cost + 20% on cost
= $400 + 20%  = $480 ($400 * 1.2)
Separate performance values:
Sale of window = $1,920   = $1,896 ($1,920/$2,400 * $2,370)
Installation =             480   =      474 ($480/$2,400 * $2,370)
Total =                 $2,400  = $2,370
c. If Ivanhoe Windows is unable to develop a reliable estimate for the fair value of the installation, both payments received will be attributed to the Sales Revenue without identifying separate performance values.