Explanation
The purpose of this formula is to demonstrate how other formulas and functions can be nested inside the IF function.
The IF function takes three arguments like this:
=IF(logical_test, value_if_true, value_if_false)
In this example, the logical test is the expression F5-E5>2:
=IF(F5-E5>2 // logical test
When this expression returns TRUE, the IF function calls the SUM function to sum values in data1:
SUM(data1) // when test is TRUE
When the expression returns FALSE, IF calls the SUM function to sum values in data2:
SUM(data2) // when test is false
In either case, the SUM function returns a value to the IF function, and IF returns that value as the final result.
Other calculations
This concept can be customized any way you like. To return an average instead of a sum:
=IF(F5-E5>2,AVERAGE(data1),AVERAGE(data2))
To check if F5 and F5 are both greater than 3:
=IF(AND(F5>3,E5>3),SUM(data1),SUM(data2))
And so on. The point is you can do any calculations you like inside IF. You can even create a nested IF.
Note: nesting other calculations inside a function or formula is a common practice in many more advanced formulas. It is not limited to the IF function. You can find many examples in this list.
