Apple iWork '09 - Manual (Page 215)

Chapter 9 Reference Functions 215
Except when INDEX is specified as shown in the third case above, Â row-index can’t be
omitted, and if column-index is omitted, it is assumed to be 1.
Examples
Given the following table:
=INDEX(B2:D5,2,3) returns 22, the value in the second row and third column (cell D3).
=INDEX((B2:D5,B7:D10), 2, 3, 2) returns “f”, the value in the second row and third column of the second
area (cell D8).
=SUM(INDEX(B2:D5, , 3)) returns 90, the sum of the values in the third column (cells D2 through D5).
=AVERAGE(INDEX(B2:D5,2)) returns 12, the average of the values in the second row (cells B3 through D3).
Related Topics
For related functions and additional information, see:
“COLUMN” on page 210
“INDIRECT” on page 216
“OFFSET” on page 219
“ROW” on page 221
“Listing of Reference Functions” on page 206
“Value Types” on page 36
“The Elements of Formulas” on page 15
“Using the Keyboard and Mouse to Create and Edit Formulas” on page 26
“Pasting from Examples in Help” on page 41