Answer:
Cost per letter for the correspondence activity= $ 8.75
Explanation:
Flannery Company
Given
                                  Activities Allocated      Costs Allocation Base 
Account inquiry (hours)$ 77, 000                      2,600 hours 
Account billing (lines) $ 38, 000                         19,000 lines 
Account verification (accounts) $ 20,000         30,000 accounts 
Correspondence (letters) $ 14,000                    1, 600 letters
Activities                          Northeast Office        Midwest Office 
Account inquiry (hours)          100 hours            200 hours 
Account billing (lines)             10,000 lines          9,000 lines
Account verification (accounts) 1 ,000 accounts 650 accounts 
Correspondence (letters)           50 letters               110 letters 
Calculations
 Cost per letter for the correspondence activity= Total Correspondence/ Total No of letters
Cost per letter for the correspondence activity= 14000/1600= 8.75
Cost per letter for the correspondence activity= $ 8.75
We divide the activity cost with the corresponding cost driver to get the cost per unit of activity.