Move your mouse over the circles to view country names, and then click to view their profiles. Note: It will take several minutes to draw this plot the first time you view it. After that
all plots should appear much more quickly.
Strength of correlation (R squared): 0.212 (this correlation is weak)
Pipeline transportation, Chain-type Quantity Indexes (2000 = 100) A quantity index is an index number that measures the change in the level of a quantity from a base year, apart from anychanges in relative prices. The value of the quantity index is 100 for the base year.The Bureau of Economic Analysis uses chain-type annual-weighted indexes, also known as Fisher indexes, as its measure of realoutput and prices. These measures allow for the effects of changes in relative prices and in the composition of output overtime, thereby eliminating a major source of bias inherent in fixed-weight indexes.
For each different subject, NAEP creates a scale score based on statistical procedures called item response theory (IRT). IRT is a set of statistical procedures useful in summarizing student performance across a collection of test exercises requiring similar knowledge and skills. All NAEP subject area scales are produced using these procedures. In Math and Reading, NAEP creates a scale ranging from 0-500. In Science and Writing, NAEP creates a scale ranging from 0-300.