Suppose that the mean and median of the non-negative numbers \( 21, 8, 17, a, 51, 103, b, 13, 67 \), \( (a > b) \), are \( 40 \) and \( 21 \), respectively. If the mean deviation about the median is \( 26 \), then \( 2a \) is equal to:
\( 109 \)
\( 117 \)
\( 161 \)
\( 131 \)