02 April 2008

CNN -- Not my source for math

I found what I think is an error in this CNN article on jet fuel prices. The article makes the following two claims:

1. "Jet fuel, which the Energy Department's Energy Information Administration tracked at $3.17 per gallon in New York on Tuesday, has doubled since the beginning of 2007."
2. "Jet fuel is at $3.17 per gallon, according to the Energy Department, up 200 percent from 2007."

My complaint is that "doubled" is not the same as "up 200 percent," because the latter sounds like "200% more than." If you said that jet fuel is up 100 percent from 2007, would you think that the price had stayed the same!!!

I'm operating under the following assumptions:

Given X is Fuel Prices in 2007
"Double X" = 2X
"Up 200 percent" = X + 2.00*X = 3X
"200 percent of X" = 2.00*X = 2X

Accordingly, I think CNN should have said, "Jet fuel is at... 200 percent of its 2007 level," or alternatively, "up 100 percent from 2007."

What do you think?! By the way I did check the underlying numbers and verified that the fuel levels today are 2X. Also, I have a little evidence from the site (taken 31 Mar 08):

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