Saturday, August 23, 2008

More Math

Maybe I'm missing something but this article confused me. It tells about two teens who collected samples of sushi and had the samples tested to see if the fish was correctly labeled. Reportedly, 25% of the tested sushi turned out to be mislabeled.

The results showed that 25 percent of the girls' samples were mislabeled: half of the restaurant samples and six out of 10 grocery store samples.

If 50% of the restaurant samples were mislabeled and 60% of the grocery store samples were mislabeled how could the final result be 25%? Maybe they meant 50% of the restaurant samples were mislabled and 6 samples of all the samples taken from 10 grocery stores were mislabled? There were 60 samples altogether. If 18 of the samples were from restaurants and 42 were from 10 grocery stores then 15 of the 60 were mislabeled, or 25% of all samples.

But that isn't how the article reads to me.

1 comment:

JohnnyB said...

The way I decipher it, overall they took 60 samples from 14 locations and 15 samples were mislabeled.2 of the restaurants and 6 of the stores had mislabeled samples, but it doesn't say how the 15 mislabeled samples were distributed among those locations. It that sense, it's a poorly written story and my experience is that reporters don't really understand the statistics they include in their stories.