Structuring a Keep$-$or$-$Drop Product Line Problem with Complementary Effects

Shown below is a segmented income statement for Hickory Company's three wooden flooring product lines:

Sales revenue

Less: Variable expenses

Contribution margin

Less direct fixed expenses:

same.

Required:

If the parquet product line is dropped, what is the contribution margin for the strip line?

$x$

For the plank line?

Which alternative $($keep or drop the parquet product line$)$ is now more cost effective and by how much?

$$ by

x