What statistical principle is used to evaluate the reliability of the Intoxilyzer 9000’s results?

The statistical principle used to evaluate the reliability of the Intoxilyzer 9000’s results is standard deviation. Standard deviation measures the amount of variation or dispersion in a set of values. In the context of the Intoxilyzer 9000, it indicates how consistent the test results are when repeated under similar conditions. A low standard deviation means that the test results are close to the mean (average), suggesting high reliability and accuracy in the readings. This is crucial when determining whether a person's blood alcohol concentration is above legal limits, as reliable results are essential for enforcement and legal purposes.

While variance, mean, and probability are all relevant statistical concepts, they do not directly address the consistency of individual test results in the same way that standard deviation does. Variance is the square of the standard deviation and serves as a measure of spread but does not provide as straightforward a context for interpreting the reliability of repeated measurements. The mean provides an average, but it lacks information about the reliability of those measurements. Probability, on the other hand, relates to the likelihood of events occurring but does not measure the variability of the results themselves. Thus, standard deviation is the most fitting choice when assessing the reliability of the Intoxilyzer 9000’s results