Here is a typical statement made by the​ media: "Based on a recent​ study, pennies weigh an average of 2.5 grams with a margin of error of 0.006​ gram." What important and relevant piece of...

Here is a typical statement made by the​ media: "Based on a recent​ study, pennies weigh an average of 2.5 grams with a margin of error of 0.006​ gram." What important and relevant piece of information is omitted from that​ statement? Is it OK to use the word​ "average"?