NBC can't do math

On a story tonight about large serving sizes of cheap food, NBC noted that the average dinner plate has gone from 9" in diameter in the 1960s to 12" today, "or 33% larger". But, from a food point of view, it's area that matters, and a 12" plate is 77% larger in area than a 9" plate (because area grows as the square of the radius).

Do the math, NBC!