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?
<spanclass=′latex−bold′>(A)</span>50<spanclass=′latex−bold′>(B)</span>60<spanclass=′latex−bold′>(C)</span>75<spanclass=′latex−bold′>(D)</span>90<spanclass=′latex−bold′>(E)</span>100