Apple iWork '09 - Manual (Page 358)

Using Logical and Information Functions Together
Logical and information functions are often used together in a formula. Although
logical functions are used independently, it is rare for an information function to
be used on its own. This section includes more complex examples to illustrate how
the use of several logical and information functions in a single formula can be very
powerful.
Adding Comments Based on Cell Contents
This example uses IF, AND, OR, and ISBLANK to add comments to a table based on
existing cell contents. The IF function is quite powerful, especially when combined
with other logical functions like OR and AND.
Assume that you are a college professor and one of the graduate assistants has
handed you a table containing the names of students and their recent exam results.
You want to quickly identify the following situations:
The student passed, but should come in for a special study session (score in the Â
range 61–75).
There is an error (negative test score, a test score over 100, or no test score) in the
Â
data.
The student failed the exam (score of 60 or below).
Â
Breaking this into parts, the functions below will determine each of the things you
wish to know. When put together, you will be able to quickly glance at the table and
see the desired information. For purposes of the expressions below, assume the first
student’s name is in cell A2, and the first test score in cell B2.
358 Chapter 13 Additional Examples and Topics