Practice Exam 3 - Question 3

Dear Ned

On Practice Exam 3 - Question 3 :

I get 2.96% for the Geometric Return, I am not sure what might be the problem, but This is my line of code:

=GEOMEAN(D6:D28+1)-1

Btw I am a little confused why we add 1 in parentheses and subtract it outside. 

Best Regards,

Mani