Final answer:
To find the value of x, we can use the fact that the median of the given numbers is 9. By finding the average of the two middle numbers, we can set up an equation and solve for x. The answer is option B, 8.
Step-by-step explanation:
To find the median, we need to arrange the numbers in ascending order. The given numbers are x-4, x, 2x, and 2x + 12. We know that the median is 9. Since there are four numbers, the median will be the average of the two middle numbers. So, we have (x + 2x) / 2 = 9. Simplifying this equation, we get 3x / 2 = 9. Solving for x, we find x = 6. Therefore, the answer is option B, 8.