

   BBeellggiiuumm PPhhoonnee CCaallllss 11995500--11997733

   AArrgguummeennttss::

       year: The last two digits of the year.

      calls: The number of telephone calls made (in millions of
             calls).

   SSUUMMMMAARRYY::

        The `phones' data frame has 24 rows and 2 columns.

   DDAATTAA DDEESSCCRRIIPPTTIIOONN::

        This data frame contains the following columns:

   SSOOUURRCCEE::

        The data were obtained from

        Rousseeuw, P.J. and Leroy, A.M. (1987) Robust Regres-
        sion and Outlier Detection. John Wiley.

   OOTTHHEERR RREEFFEERREENNCCEESS::

        Davison, A.C. and Hinkley, D.V. (1997) Bootstrap Meth-
        ods and Their Application. Cambridge University Press.

        Venables, W.N. and Ripley, B.D. (1994) Modern Applied
        Statistics with Splus. Springer-Verlag

