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Flashcards in Chapter 4 Deck (14)
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1

average

The sum of several values divided by the number of values. Also called mean.

2

blank solution

A solution not intended to contain analyte. It could be made from all reagents - except unknown- that would be used in an analytical procedure. Analyte signal measured with a blank solution could be due to impurities in the reagents or, possibly, interference.

3

calibration curve

A graph showing the value of some property versus concentration of analyte. When the corresponding property of an unknown is measured, its concentration can be determined from the graph.

4

confidence interval

Range of values within which there is a specified probability that the true value lies.

5

degrees of freedom

In statistics, the number of observations minus the number of parameters estimated from the observations.

6

dynamic range

Range of analyte concentration over which a change in concentration gives a change in detector response.

7

Gaussian distribution

Theoretical bell-shaped distribution of measurements when all error is random. The center of the curve is the mean and the width is characterized by the standard deviation.

8

Grubbs test

Statistical test used to decide whether to discard a datum that appears discrepant.

9

linear range

Concentration range over which the change in detector response is proportional to the change in analyte concentration.

10

linear response

The case in which the analytical signal is directly proportional to the concentration of analyte.

11

mean

The sum of several values divided by the number of values.

12

method of least squares

Process of fitting a mathematical function to a set of measured points by minimizing the sum of the squares of the distances from the points to the curve.

13

outlier

A datum that lies far from the other data in a set of measurements.

14

standard deviation

A statistic measuring how closely data are clustered about the mean value.