Answer:
Shamrock, Inc.
Adjusting Journal Entries:
1. Debit Insurance Expense $280
 Credit Prepaid Insurance $280
 To record insurance expense for the month.
2. Debit Supplies Expense $1,890
 Credit Supplies $1,890
 To record supplies expense for the month.
3. Debit Depreciation Expense - Equipment $170
 Credit Accumulated Depreciation- Equipment $170
 To record depreciation expense for the month.
4. Debit Unearned Service Revenue $5,880
 Credit Service Revenue $5,880
 To record earned service revenue for the month.
Step-by-step explanation:
a) Data:
Selected Accounts:
 Debit Credit 
Supplies 2,780 
Prepaid Insurance 2,240 
Equipment 25,500 
Unearned Service Revenue 14,700
b) The above adjusting entries at the end of March are made by Shamrock in order to accurately recognize its revenue and expenses for the month of March. These entries are in line with the accrual concept and matching principle of generally accepted accounting principles. They require that revenues or expenses earned or incurred in a period be recognized and matched in the affected period, whether cash was exchanged or not.