Final answer:
The correct proportion of sales from new stores in the Midwest region cannot be determined without the relevant data directly aligned with this specific question.
Step-by-step explanation:
The student asks for the proportion of sales from new stores in the Midwest region. Referring to the data provided, none indicate a specific figure for the sales of new stores in the Midwest region that matches the options given (85, 18, 27, 15). However, there is a number .279 or 27.9% listed without context which may suggest it is the closest answer, being approximately 27%. But without clear connection to the question, this cannot be confirmed as the correct answer. When faced with questions like this, it is crucial to ensure the data presented aligns directly with the question asked.