AMC 12 2016a Problem 4

The mean, median, and mode of the $7$ data values $60, 100, x, 40, 50, 200, 90$ are all equal to $x$. What is the value of $x$?

\textbf{(A)}\ 50 \textbf{(B)}\ 60 \textbf{(C)}\ 75 \textbf{(D)}\ 90 \textbf{(E)}\ 100