Keep this in mind when criticizing an argument, such as on the GRE "Analyze an Argument" task in the writing section. I'm not sure if the "might" in the clip heading is logically necessary or not. I'm just trying to be cautious.

I had this demonstrated to me when I was 11 in my first term at high school. The geography teacher discussed a graph which showed an almost perfect correlation between the increase in UK pig iron production and UK birth rate in 1951.