Answer: The required selling price of the dining room set is $1240.
Step-by-step explanation: We are given to find the selling price of a dining room set at Macy's if the actual cost is $800 and 55% markup on the selling price.
The markup price of the dining room set is given by

Therefore, the selling price of the dining room set is given by
S.P. = 800 + M.P. = 800 + 440 = 1240.
Thus, the required selling price of the dining room set is $1240.