An Exercise in Estimation

Consider the following imaginary newspaper article. It is not too different from what we might see in any of the local dailies, in that contains statements made by so-called experts concerning measurements and their consequences.

Lead Rain From Motor Vehicle Exhausts! Senior scrap metal industry officials claimed yesterday that $20 000 worth of lead from motor vehicle exhausts is spread over Sydney every day. Dr Anitmony Bismuth, of the Rare, Toxic and Preferably Valuable Metals Recycling Centre, said that a container load of lead could be removed from the city streets every day using her company's unique Magnetic Flocculation System. However, Mr Ozone Friendly, of the Totally Green Organization, claimed that the Magnetic Flocculation technology was environmentally unsound ... (and so on)

In the next few pages, we are going to examine the two quantitative claims made in this article: that $20 000 of lead is produced every day and that this makes up an entire container load.