Stock indexes are collections of stocks meant to represent the market or a portion of it—they are used by investors as benchmarks against which to compare the performance of their own portfolios.

The consumer price index is a weighted average collection of the prices of common goods and services. Changes in the CPI over time are used to estimate the rate of inflation. The consumer price ...

The refractive index of a vacuum is 1.0 ... 3.5 Germanium 4.0 ** = air is a tiny franction greater than 1.0 THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.