In this task, you are given a list. This list contains many lists of integers. The list is several items written within a []. Your task is to find the maximum number among the members of each inner list. The output should be a list comprised of the maximums with the same order as the internal lists.
[[20, -172], [95, 49, 48], [-180, -76, -189, 91, 62, 8, 34], [-60, 90, -34, 34, 28, -52, 31]]