When the tractor-trailer hit her car, sami suffered a concussion. her memory was impaired and she could not recall events from the accident. which brain structure was injured?

The answer is Hippocampus. The hippocampus have its place to the limbic system and plays significant roles in the joining of information from short-term memory (STM) to long-term memory (LTM), and in spatial memory that assists navigation. It is involved with learning and memory, especially the formation of new memories. 

the median of the data is 4.

step-by-step explanation:

the median means the middle number of a given number.

to decide which one is the median, arrange in ascending or descending order. but sometimes, you may find two(2) number in the middle, but it's easy, just add them together and divide by 2.

so,   determine the median of the data. 2, 3, 3, 4, 5, 7, 9

it is already arranged, count 3 times forward and 3 backward and the one left is your answer.

2,3,3,4,5,7,9

our answer is 4.

hope this !