Final answer:
The question doesn't provide enough real-world context for an exact answer, but the maximum speed for opening cabin doors can depend on many factors including aircraft design. Refer to your study materials for the specific context of the scenario presented in your question.
Step-by-step explanation:
Unfortunately, the question does not provide sufficient information to provide a precise answer. In real-world scenarios, the maximum allowable speed for opening cabin doors relies on many factors, not strictly limited to the presence of soundproofing. These factors can include the aircraft's design, structural integrity of the doors and frame, and construction of the soundproofing material. However, for the purpose of your test or assignment, the answer should be within the options provided - 70 KIAS, 100 KIAS, 120 KIAS, or 150 KIAS. Please refer to your class materials, notes or textbook to identify the correct answer based on the specific scenario mentioned (i.e., soundproofing installed aft of station 379).
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