Final answer:
The median of the given data set 1; 1; 2; 3; 4; 4; 5; 5; 6; 7; 7; 8; 9 is 6.
Step-by-step explanation:
The data set 1; 1; 2; 3; 4; 4; 5; 5; 6; 7; 7; 8; 9 has a total of 13 values. Since there is an odd number of values, the median will be the middle value, which is the 7th value in this case.
To find the median, we count from the smallest value in the ordered list until we reach the 7th value. In this case, the median is 6.
Based on the given choices, none of them could be the value of x because the median of the data set is 6.