The following pages were corrected in the fourth printing, which took
place in May, 2006.

pg010  The order of the limits in (1.10) was changed for formal
       correctness.

pg092-33 There were minor changes on these two pages to avoid referring
         to the number of elements in a vector as its length.

pg170-71 There are several changes on these pages to resolve a slight
         notational inconsistency. What used to be beta in some places
         and beta_2 in others is now beta_2 throughout.

pg192  There was a minor notational change in equation (5.25) and
       immediately following it to avoid possible confusion.

pg229  There was a minor change on this page to avoid referring to the
       number of elements in a vector as its length.

pg253  The way Exercise 6.5 was stated was changed to avoid possible
       confusion about the relationship with equation (6.20).

pg319  There was a minor change at the bottom of the page to avoid
       implying something incorrect.

pg348  In the first line, u_i was replaced by u_i^*.

pg412  A minor notational error in equation (10.31) has been corrected.

pg452  There was a minor change on this page to avoid referring to the
       number of elements in a vector as its length.

pg464  There was a minor change on this page to avoid referring to the
       number of elements in a vector as its length.

pg468  There was a minor change on this page to avoid referring to the
       number of elements in a vector as its length.

pg492  There were a few changes just before equation (11.84) to make it
       clear that the data are independent.

pg500  A notational error was corrected in the second line of
       Exercise 11.31.

pg516  There was a minor change on this page to avoid referring to the
       number of elements in a vector as its length.

pg597  There was a minor change on this page to avoid referring to the
       number of elements in a vector as its length.

pg599  The last sentence in Exercise 13.2 was changed again to correct an
       error introduced in the third printing.

pg602  There were two errors in the statement of Exercise 13.17, most
       seriously in the displayed equation.

pg651  There was a minor change on this page to avoid referring to the
       number of elements in a vector as its length.