Microsoft Office Tutorials and References

In Depth Information

**Specialized Lookup Formulas**

without using a lookup table. Rather, the information in the lookup table is hard-coded into an

array constant. See Chapter 14 for more information about array constants.

=VLOOKUP(B2,{0,”F”;40,”D”;70,”C”;80,”B”;90,”A”},2)

Another approach, which uses a more legible formula, is to use the LOOKUP function with two

array arguments:

=LOOKUP(B2,{0,40,70,80,90},{“F”,”D”,”C”,”B”,”A”})

Finally, whenever you can easily convert your input, the number grade in this case, into the

integers 1 to 254, the CHOOSE function becomes an option. The number grades are divided by 10,

the decimal is stripped off, and 1 is added to it to produce the numbers 1 to 11. The remaining

arguments define the return values for those 11 options.

=CHOOSE(TRUNC(B2/10)+1,”F”,”F”,”F”,”F”,”D”,”D”,”D”,”C”,”B”,”A”,”A”)

Calculating a grade point average

A student’s
grade point average
(GPA) is a numerical measure of the average grade received for

classes taken. This discussion assumes a letter grade system, in which each letter grade is

assigned a numeric value (A=4, B=3, C=2, D=1, and F=0). The GPA comprises an average of the

numeric grade values, weighted by the credit hours of the course. A one-hour course, for

example, receives less weight than a three-hour course. The GPA ranges from 0 (all Fs) to 4.00

(all As).

Figure 8-11 shows a worksheet with information for a student. This student took five courses, for

a total of 13 credit hours. Range B2:B6 is named
CreditHours.
The grades for each course appear

in column C (Range C2:C6 is named
Grades
). Column D uses a lookup formula to calculate the

grade value for each course. The lookup formula in cell D2, for example, follows. This formula

uses the lookup table in G2:H6 (named
GradeTable
).

=VLOOKUP(C2,GradeTable,2,FALSE)