

   BBrroowwnnlleeee''ss SSttaacckk LLoossss PPllaanntt DDaattaa

        data(stackloss)

   FFoorrmmaatt::

        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

   DDeessccrriippttiioonn::

        (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.''

   SSoouurrccee::

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

   RReeffeerreenncceess::

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

   EExxaammpplleess::

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

