hello,
i'm trying to reprogram the NPV function as in Excel but i can't seem
to understand how excel gets the result it is giving

for instance in the help i see this example:
annual discount rate: 10%
initial cost: 10000
return first year: 3000
return second year: 4200
return third year: 6800

Can someone explain me (step by step) how excel is giving me the result
of 1188.44?

i thought it was:
3000/1.1 + 4200/1.21 + 6800/1.331 but that gives me something else?

Any help would be appreciated,
Stig