Certain operating information is shown below for Harris Department Store:

The managers are disappointed with the operating results of department R. They do not believe that competition will permit raising prices; however, they believe that spending 

\($10,000\) more for promoting this department’s products will increase the physical volume of products sold by 20%.
An alternative is to discontinue department R and use the space to expand department S. It is believed that department S’s physical volume of products sold can thus be increased 35%. Special sales personnel are needed, however, and department S’s traceable expenses would increase by \($48,000\).
Neither alternative would appreciably affect the total common departmental expense.
Required

a. Calculate the contribution now being made to common expenses by department R, by department S, and by the combination of other departments.

b. Which of the two alternatives should management choose: increase promotional outlays for department R, or discontinue department R and expand department S? Support your answer with calculations.

Sales... Traceable expenses. Common expenses Gross profit percentage. Department R Department S $320,000 56,000 $480,000 88,000 48,000 64,000 30% 40% All Other Departments $1,120,000 320,000 160,000 50%