Answer: (-6, 5)
<u>Step-by-step explanation:</u>
Use the Midpoint Formula: 
Separate the x's and y's and solve them individually:

So, the k-coordinate is (-6, 5)
C. 5 bc u jus gotta add it on the calculator
52 - 37 = 15
67 - 52 = 15
82 - 67 = 15
The common difference for this arithmetic sequence is 15.
Answer: C.