## Brownlee's Stack Loss Plant Data

## Usage

    data(stackloss)

## Format

A data frame with 21 observations on 4 variables.

[,1] | x1 | Air.Flow | Flow of cooling air
[,2] | x2 | Water.Temp | Cooling Water Inlet
|  |  | Temperature
[,3] | x3 | Acid.Conc. | Concentration of acid
|  |  | [per 1000, minus 500]
[,4] | y | stack.loss | Stack loss

## Description

(Brownlee, cited by Dodge, slightly reformatted by MM): ``Obtained from 21 days of operation of a plant for the oxidation of ammonia (NH3) to nitric acid (HNO3). The nitric oxides produced are absorbed in a countercurrent absorption tower.

`x1` represents the rate of operation of the plant. `x2` is the temperature of cooling water circulated through coils in the absorption tower. `x3` is the concentration of the acid circulating, minus 50, times 10: that is, 89 corresponds to 58.9 per cent acid. `y` (the dependent variable) is 10 times the percentage of the ingoing ammonia to the plant that escapes from the absorption column unabsorbed; that is, an (inverse) measure of the over-all efficiency of the plant.''

## Source

Brownlee, K.A. (1960, 2nd ed. 1965) Statistical Theory and Methodology in Science and Engineering; John Wiley, NY; pp. 491--500

## References

Yadolah Dodge, The Guinea Pig of Multiple Regression, Robust Statistics, Data Analysis, and Computer Intensive Methods; In Honor of Peter Huber's 60th Birthday, 1996, Lecture Notes in Statistics 109, Springer-Verlag, New York.

## Examples

    data(stackloss)
    summary(lm.stack <- lm(stack.loss ~ stack.x))

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