When you estimate a number you decide approximately, or roughly, how big that number is. To estimate accurately, you need to have a good understanding of the value and order of numbers. A number line ...

Only a few countries have official population statistics which are sufficiently accurate to produce reliable estimates of death rates at high ages. For other countries, there are several methods which ...

This paper presents the results of a study with two main objectives: (1) to investigate an extension of some principles recently developed in the theory of cluster sampling, and (2) to determine the ...

Turnstiles and ticket stubs are surefire ways to track the number of fans who attend sporting events, concerts and plays. But when masses gather for a gateless event—as they did last weekend to ...