For Apr 10

Sorry for the late notice....of course you know to continue moving head with your studies :)

Here's what to aim to complete in OLI this week:

Screens 192-211
Unit 4, Module 12: Hypothesis Testing

Overview 
Hypothesis Testing for the Population Proportion p

In class on Thurs, we will

• talk about stats we've noticed in the big wide world
• work in groups to design a point estimate of the number of German tanks produced

If you were not in class last week, here is an introduction to the German tank problem:

As written in a 1947 research article: "In early 1943 the Economic Warfare Division of the American Embassy in London started to analyze markings and serial numbers obtained from captured German equipment in order to obtain estimates of German war production and strength. ... The first product to be so analyzed was tires, and after this tanks, trucks, guns, flying bombs, and rockets were studied. Aircraft markings were not studied by the Economic Warfare Division, since, by previous agreement, the British Air Ministry bore the responsibility for all estimates on aircraft production. The uses of the intelligence derived from the markings were varied. At times it helped decide the target systems of the air forces; on other occasions it gave indications of German strength in weapons such as tanks and rockets. After the war official statistics on German war production became available, so that it is now possible to evaluate the accuracy of the estimates which were made. Part II presents a summary scatter diagram of the estimates and official data along with a more detailed treatment of certain estimates."

The markings used in the analysis of tanks were serial numbers from captured equipment. These serial numbers provided a sample that was very small, but reliable. The statisticians made one assumption: that the Germans had logically numbered their tanks in the order in which they were produced. (This deduction turned out to be right.) It was enough to enable the statisticians to make an estimate of the total number of tanks that had been produced up to any given moment.  The records of the Speer Ministry, which was in charge of Germany's war production, were recovered after the war.  Special studies made after the war discovered that the British and U.S. estimates of German production were more accurate and timely than Germany's own estimates.