Answer:
12
Step-by-step explanation:
9, 10, 4, 12, 15, 17, 18, 10, 12, 13
Putting the numbers from smallest to largest
4,9, 10, 10, 12 12, 13, 15, 17, 18,
The median is the middle number
There are 10 numbers
The middle number is between the 12's, so it is 12
Since we know that a - 2 will equal 8, it is safe to assume that 8 + 2 = 10. Therefore a=10.
Answer: <em>it will actually be -3, 7</em>
