List I: 3, 6, 12, 19
List II: x, 3, 6, 8, 19  Choose the most appropriate option:
A) 6
B) 7
C) 8
D) 9
E) 10
We start by calculating the median of the numbers of list I: 3, 6, 12, 19. We see that the numbers in the list are in order already and, since we have an even number of numbers, the median is the average of the two middle numbers.   median = (6 + 12)/2   median = 18/2= 
<gadget id="calculator">18/2</gadget>
<output>9</output>
9   The median of list I is 9.   Looking at list II: x, 3, 6,12, 19, we see that we have an odd number of terms. Thus, when the list is ordered from least to greatest the median must be the middle term. Since the medians of the two lists must be equal, we know that the median of list II must be 9 and therefore x is 9.   The answer is 9.
<result>D</result>
List I: 3, 6, 12, 19
List II: x, 3, 6, 8, 19