Explanation:
The adjusting entries are as follows
a. Insurance expense A/c Dr $1,200
To Prepaid insurance A/c $1,200
(Being the insurance expense is recorded)
The computation is shown below:
= $3,000 - $1,800
= $1,200
b. Account receivable Dr $1,100
To Service revenue $1,100
(Being the service performed is recorded)
c. Salaries and wages expenses Dr $800
To Salaries and wages payable $800
(Being the salaries and wages expense is recorded)