ZTEST MACRO

This macro implements the large sample standard normal approximation
test for equality of two independent proportions. It is used by saving
the file to the appropriate directory containing your SPSS files. The
name ztest.sps is suggested, but any allowable name will do. After the
file has been saved, it is executed by opening a syntax window and
running two commands. The first command is an INCLUDE command, in
which you name the macro file for SPSS to include.

The second command specifies the arguments needed to run the macro.
The syntax is "z r1 n1 r2 n2 ." The z calls this macro; r1 is to be
replaced with the number of responses in the first group, n1 with the
total number observed in the first group, and the same with r2 and n2
for the second group. (For example, if each group contains 100 total
observations and there are 50 and 60 responses in the two groups, the
syntax would be:

include ztest.sps .
z 50 100 60 100 .

You do not have to have a data set defined to run the macro, as it
creates one using an INPUT PROGRAM. If you have data in your data
editor in SPSS for Windows, make sure to save it before executing
this macro, or you will lose that data. If you execute the macro more
once in a session, you will get a warning message on subsequent
invocations about multiple calls to the same macro. This message can
be ignored.