Performance IQ scores vs. brain size. A study examined brain size (measured as pixels counted in a digitized magnetic resonance image [MRI] of a cross section of the brain) and IQ (4 performance scales of the Wechsler IQ test) for college students. The scatterplot shows the Performance IQ scores vs.

Brain Size. Comment on the association between Brain Size and Performance IQ as seen in the scatterplot. (Data in IQ brain)

Performance IQ 140 120 100 80 80 xx ++ xxxx 825 975 Brain Size (pixels)