The Regression Range (or Matrix Range) defined when using the Regression option in the Matrix dialog box must include at least one row more that the number of columns specified. For example:
If your Regression Range includes one Dependant variable and 2 Independant variables (3 columns) then at least 4 rows (observations) must be defined (5 if column titles are included).
If fewer rows than columns are defined, the message "Insufficient number of observations" will be returned. If the same number of rows and columns are specified, the message "No observations" will be displayed. Valid results are obtained only when there are more rows (observations) than columns (variables).