Answer:
y will be the dependent variable, and x will be the independent variable.
So y is affected by x.
Regarding the problem you attached, consider if IQ affects job performance, or if job performance affects IQ.
I would say that IQ may affect job performance (as job performance does not affect IQ), so in this case x will be IQ and y will be job performance.
When data is presented in tables, it is usual for the x values to be on the left and the y values to be on the right (though, not in every case, of course!).
